Network Working Group                                 P. Resnick, Editor
Request for Comments: 2822                         QUALCOMM Incorporated
Obsoletes: 822                                                April 2001
Category: Standards Track
                        Internet Message Format

Status of this Memo


This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.

この文書は、インターネットコミュニティのためのインターネット標準トラックプロトコルを指定し、改善のための議論と提案を要求します。このプロトコルの標準化状態と状態への「インターネット公式プロトコル標準」(STD 1)の最新版を参照してください。このメモの配布は無制限です。

Copyright Notice


Copyright (C) The Internet Society (2001). All Rights Reserved.




This standard specifies a syntax for text messages that are sent between computer users, within the framework of "electronic mail" messages. This standard supersedes the one specified in Request For Comments (RFC) 822, "Standard for the Format of ARPA Internet Text Messages", updating it to reflect current practice and incorporating incremental changes that were specified in other RFCs.

この規格は、「電子メール」メッセージの枠組みの中で、コンピュータユーザの間で送信されるテキストメッセージの構文を指定します。この規格は、現在の慣行やその他のRFCで指定された増分変更を組み込むことを反映して、それを更新し、「ARPAインターネットテキストメッセージの形式の規格」のRFC(Request for Comments)822で指定されたものを優先します。

Table of Contents


   1. Introduction ............................................... 3
   1.1. Scope .................................................... 3
   1.2. Notational conventions ................................... 4
   1.2.1. Requirements notation .................................. 4
   1.2.2. Syntactic notation ..................................... 4
   1.3. Structure of this document ............................... 4
   2. Lexical Analysis of Messages ............................... 5
   2.1. General Description ...................................... 5
   2.1.1. Line Length Limits ..................................... 6
   2.2. Header Fields ............................................ 7
   2.2.1. Unstructured Header Field Bodies ....................... 7
   2.2.2. Structured Header Field Bodies ......................... 7
   2.2.3. Long Header Fields ..................................... 7
   2.3. Body ..................................................... 8
   3. Syntax ..................................................... 9
   3.1. Introduction ............................................. 9
   3.2. Lexical Tokens ........................................... 9
   3.2.1. Primitive Tokens ....................................... 9
   3.2.2. Quoted characters ......................................10
   3.2.3. Folding white space and comments .......................11
   3.2.4. Atom ...................................................12
   3.2.5. Quoted strings .........................................13
   3.2.6. Miscellaneous tokens ...................................13
   3.3. Date and Time Specification ..............................14
   3.4. Address Specification ....................................15
   3.4.1. Addr-spec specification ................................16
   3.5 Overall message syntax ....................................17
   3.6. Field definitions ........................................18
   3.6.1. The origination date field .............................20
   3.6.2. Originator fields ......................................21
   3.6.3. Destination address fields .............................22
   3.6.4. Identification fields ..................................23
   3.6.5. Informational fields ...................................26
   3.6.6. Resent fields ..........................................26
   3.6.7. Trace fields ...........................................28
   3.6.8. Optional fields ........................................29
   4. Obsolete Syntax ............................................29
   4.1. Miscellaneous obsolete tokens ............................30
   4.2. Obsolete folding white space .............................31
   4.3. Obsolete Date and Time ...................................31
   4.4. Obsolete Addressing ......................................33
   4.5. Obsolete header fields ...................................33
   4.5.1. Obsolete origination date field ........................34
   4.5.2. Obsolete originator fields .............................34
   4.5.3. Obsolete destination address fields ....................34
   4.5.4. Obsolete identification fields .........................35
   4.5.5. Obsolete informational fields ..........................35
   4.5.6. Obsolete resent fields .................................35
   4.5.7. Obsolete trace fields ..................................36
   4.5.8. Obsolete optional fields ...............................36
   5. Security Considerations ....................................36
   6. Bibliography ...............................................37
   7. Editor's Address ...........................................38
   8. Acknowledgements ...........................................39
   Appendix A. Example messages ..................................41
   A.1. Addressing examples ......................................41
   A.1.1. A message from one person to another with simple
          addressing .............................................41
   A.1.2. Different types of mailboxes ...........................42
   A.1.3. Group addresses ........................................43
   A.2. Reply messages ...........................................43
   A.3. Resent messages ..........................................44
   A.4. Messages with trace fields ...............................46
   A.5. White space, comments, and other oddities ................47
   A.6. Obsoleted forms ..........................................47
   A.6.1. Obsolete addressing ....................................48
   A.6.2. Obsolete dates .........................................48
   A.6.3. Obsolete white space and comments ......................48
   Appendix B. Differences from earlier standards ................49
   Appendix C. Notices ...........................................50
   Full Copyright Statement ......................................51
1. Introduction
1. はじめに
1.1. Scope
1.1. 範囲

This standard specifies a syntax for text messages that are sent between computer users, within the framework of "electronic mail" messages. This standard supersedes the one specified in Request For Comments (RFC) 822, "Standard for the Format of ARPA Internet Text Messages" [RFC822], updating it to reflect current practice and incorporating incremental changes that were specified in other RFCs [STD3].

この規格は、「電子メール」メッセージの枠組みの中で、コンピュータユーザの間で送信されるテキストメッセージの構文を指定します。この規格は、[RFC822]、現在の慣行やその他のRFC [STD3]で指定された増分変更を組み込むことを反映して、それを更新し、「ARPAインターネットテキストメッセージの形式の規格」のコメント(RFC)822、の要求で指定されたものを優先します。

This standard specifies a syntax only for text messages. In particular, it makes no provision for the transmission of images, audio, or other sorts of structured data in electronic mail messages. There are several extensions published, such as the MIME document series [RFC2045, RFC2046, RFC2049], which describe mechanisms for the transmission of such data through electronic mail, either by extending the syntax provided here or by structuring such messages to conform to this syntax. Those mechanisms are outside of the scope of this standard.

この規格は、専用のテキストメッセージのための構文を指定します。特に、電子メールメッセージ内の画像、オーディオ、または構造化データの他の種類の伝送のための準備を行いません。ここで提供される構文を拡張することによってか、この構文に準拠するように、このようなメッセージを構造化することにより、いずれか、電子メールを通じて、このようなデータの伝送のためのメカニズムを説明し、このようなMIMEドキュメントシリーズ[RFC2045、RFC2046、RFC2049]として発行され、いくつかの拡張機能は、ありますが、 。これらのメカニズムは、この規格の範囲外です。

In the context of electronic mail, messages are viewed as having an envelope and contents. The envelope contains whatever information is needed to accomplish transmission and delivery. (See [RFC2821] for a discussion of the envelope.) The contents comprise the object to be delivered to the recipient. This standard applies only to the format and some of the semantics of message contents. It contains no specification of the information in the envelope.

電子メールの文脈では、メッセージは封筒と内容を持つと見ています。エンベロープは、送信と配信を実現するために必要なものは何でも情報が含まれています。 (封筒の議論のために[RFC2821]を参照。)コンテンツオブジェクトが受信者に配信されるように含みます。この規格は、専用フォーマットとメッセージ内容のセマンティクスの一部に適用されます。これは、エンベロープ内の情報のない仕様が含まれていません。

However, some message systems may use information from the contents to create the envelope. It is intended that this standard facilitate the acquisition of such information by programs.


This specification is intended as a definition of what message content format is to be passed between systems. Though some message systems locally store messages in this format (which eliminates the need for translation between formats) and others use formats that differ from the one specified in this standard, local storage is outside of the scope of this standard.


Note: This standard is not intended to dictate the internal formats used by sites, the specific message system features that they are expected to support, or any of the characteristics of user interface programs that create or read messages. In addition, this standard does not specify an encoding of the characters for either transport or storage; that is, it does not specify the number of bits used or how those bits are specifically transferred over the wire or stored on disk.


1.2. Notational conventions
1.2. 表記規則
1.2.1. Requirements notation
1.2.1. 要件表記

This document occasionally uses terms that appear in capital letters. When the terms "MUST", "SHOULD", "RECOMMENDED", "MUST NOT", "SHOULD NOT", and "MAY" appear capitalized, they are being used to indicate particular requirements of this specification. A discussion of the meanings of these terms appears in [RFC2119].

このドキュメントは時折大文字で現れる用語を使用しています。ときの用語は、「MUST」、「推奨」「SHOULD」、「NOT MUST」、「SHOULD NOT」、および大文字表示される「MAY」、彼らは、この仕様の特定の要件を示すために使用されています。これらの用語の意味の議論は[RFC2119]に表示されます。

1.2.2. Syntactic notation
1.2.2. 構文記法

This standard uses the Augmented Backus-Naur Form (ABNF) notation specified in [RFC2234] for the formal definitions of the syntax of messages. Characters will be specified either by a decimal value (e.g., the value %d65 for uppercase A and %d97 for lowercase A) or by a case-insensitive literal value enclosed in quotation marks (e.g., "A" for either uppercase or lowercase A). See [RFC2234] for the full description of the notation.


1.3. Structure of this document
1.3. このドキュメントの構造

This document is divided into several sections.


This section, section 1, is a short introduction to the document.


Section 2 lays out the general description of a message and its constituent parts. This is an overview to help the reader understand some of the general principles used in the later portions of this document. Any examples in this section MUST NOT be taken as specification of the formal syntax of any part of a message.


Section 3 specifies formal ABNF rules for the structure of each part of a message (the syntax) and describes the relationship between those parts and their meaning in the context of a message (the semantics). That is, it describes the actual rules for the structure of each part of a message (the syntax) as well as a description of the parts and instructions on how they ought to be interpreted (the semantics). This includes analysis of the syntax and semantics of subparts of messages that have specific structure. The syntax included in section 3 represents messages as they MUST be created. There are also notes in section 3 to indicate if any of the options specified in the syntax SHOULD be used over any of the others.


Both sections 2 and 3 describe messages that are legal to generate for purposes of this standard.


Section 4 of this document specifies an "obsolete" syntax. There are references in section 3 to these obsolete syntactic elements. The rules of the obsolete syntax are elements that have appeared in earlier revisions of this standard or have previously been widely used in Internet messages. As such, these elements MUST be interpreted by parsers of messages in order to be conformant to this standard. However, since items in this syntax have been determined to be non-interoperable or to cause significant problems for recipients of messages, they MUST NOT be generated by creators of conformant messages.


Section 5 details security considerations to take into account when implementing this standard.


Section 6 is a bibliography of references in this document.


Section 7 contains the editor's address.


Section 8 contains acknowledgements.


Appendix A lists examples of different sorts of messages. These examples are not exhaustive of the types of messages that appear on the Internet, but give a broad overview of certain syntactic forms.


Appendix B lists the differences between this standard and earlier standards for Internet messages.


Appendix C has copyright and intellectual property notices.


2. Lexical Analysis of Messages
2.1. General Description
2.1. 概要

At the most basic level, a message is a series of characters. A message that is conformant with this standard is comprised of characters with values in the range 1 through 127 and interpreted as US-ASCII characters [ASCII]. For brevity, this document sometimes refers to this range of characters as simply "US-ASCII characters".

最も基本的なレベルでは、メッセージは、一連の文字です。この規格に準拠しているメッセージは、[ASCII] 127までの範囲1の値を持つ文字で構成され、US-ASCII文字として解釈されます。簡潔にするために、このドキュメントは単に「US-ASCII文字」などの文字のこの範囲を指します。

Note: This standard specifies that messages are made up of characters in the US-ASCII range of 1 through 127. There are other documents, specifically the MIME document series [RFC2045, RFC2046, RFC2047, RFC2048, RFC2049], that extend this standard to allow for values outside of that range. Discussion of those mechanisms is not within the scope of this standard.


Messages are divided into lines of characters. A line is a series of characters that is delimited with the two characters carriage-return and line-feed; that is, the carriage return (CR) character (ASCII value 13) followed immediately by the line feed (LF) character (ASCII value 10). (The carriage-return/line-feed pair is usually written in this document as "CRLF".)

メッセージは文字の行に分割されています。ラインは、2文字のキャリッジ・リターンおよび改行で区切られた一連の文字です。つまり、キャリッジリターン(CR)文字(ASCII値13)は、ラインフィード(LF)文字(ASCII値10)の直後。 (キャリッジリターン/ラインフィードのペアは、通常、「CRLF」として本書で記述されています。)

A message consists of header fields (collectively called "the header of the message") followed, optionally, by a body. The header is a sequence of lines of characters with special syntax as defined in this standard. The body is simply a sequence of characters that follows the header and is separated from the header by an empty line (i.e., a line with nothing preceding the CRLF).


2.1.1. Line Length Limits
2.1.1. 行の長さの制限

There are two limits that this standard places on the number of characters in a line. Each line of characters MUST be no more than 998 characters, and SHOULD be no more than 78 characters, excluding the CRLF.


The 998 character limit is due to limitations in many implementations which send, receive, or store Internet Message Format messages that simply cannot handle more than 998 characters on a line. Receiving implementations would do well to handle an arbitrarily large number of characters in a line for robustness sake. However, there are so many implementations which (in compliance with the transport requirements of [RFC2821]) do not accept messages containing more than 1000 character including the CR and LF per line, it is important for implementations not to create such messages.


The more conservative 78 character recommendation is to accommodate the many implementations of user interfaces that display these messages which may truncate, or disastrously wrap, the display of more than 78 characters per line, in spite of the fact that such implementations are non-conformant to the intent of this specification (and that of [RFC2821] if they actually cause information to be lost). Again, even though this limitation is put on messages, it is encumbant upon implementations which display messages to handle an arbitrarily large number of characters in a line (certainly at least up to the 998 character limit) for the sake of robustness.


2.2. Header Fields
2.2. ヘッダフィールド

Header fields are lines composed of a field name, followed by a colon (":"), followed by a field body, and terminated by CRLF. A field name MUST be composed of printable US-ASCII characters (i.e., characters that have values between 33 and 126, inclusive), except colon. A field body may be composed of any US-ASCII characters, except for CR and LF. However, a field body may contain CRLF when used in header "folding" and "unfolding" as described in section 2.2.3. All field bodies MUST conform to the syntax described in sections 3 and 4 of this standard.


2.2.1. Unstructured Header Field Bodies
2.2.1. 非構造化ヘッダーフィールド機関

Some field bodies in this standard are defined simply as "unstructured" (which is specified below as any US-ASCII characters, except for CR and LF) with no further restrictions. These are referred to as unstructured field bodies. Semantically, unstructured field bodies are simply to be treated as a single line of characters with no further processing (except for header "folding" and "unfolding" as described in section 2.2.3).


2.2.2. Structured Header Field Bodies
2.2.2. 構造化ヘッダーフィールド機関

Some field bodies in this standard have specific syntactical structure more restrictive than the unstructured field bodies described above. These are referred to as "structured" field bodies. Structured field bodies are sequences of specific lexical tokens as described in sections 3 and 4 of this standard. Many of these tokens are allowed (according to their syntax) to be introduced or end with comments (as described in section 3.2.3) as well as the space (SP, ASCII value 32) and horizontal tab (HTAB, ASCII value 9) characters (together known as the white space characters, WSP), and those WSP characters are subject to header "folding" and "unfolding" as described in section 2.2.3. Semantic analysis of structured field bodies is given along with their syntax.


2.2.3. Long Header Fields
2.2.3. ロングヘッダフィールド

Each header field is logically a single line of characters comprising the field name, the colon, and the field body. For convenience however, and to deal with the 998/78 character limitations per line, the field body portion of a header field can be split into a multiple line representation; this is called "folding". The general rule is that wherever this standard allows for folding white space (not simply WSP characters), a CRLF may be inserted before any WSP. For example, the header field:


Subject: This is a test


can be represented as:


           Subject: This
            is a test

Note: Though structured field bodies are defined in such a way that folding can take place between many of the lexical tokens (and even within some of the lexical tokens), folding SHOULD be limited to placing the CRLF at higher-level syntactic breaks. For instance, if a field body is defined as comma-separated values, it is recommended that folding occur after the comma separating the structured items in preference to other places where the field could be folded, even if it is allowed elsewhere.


The process of moving from this folded multiple-line representation of a header field to its single line representation is called "unfolding". Unfolding is accomplished by simply removing any CRLF that is immediately followed by WSP. Each header field should be treated in its unfolded form for further syntactic and semantic evaluation.


2.3. Body
2.3. 体

The body of a message is simply lines of US-ASCII characters. The only two limitations on the body are as follows:


- CR and LF MUST only occur together as CRLF; they MUST NOT appear independently in the body.

- CRやLFのみCRLFとして一緒に起こらなければなりません。彼らは身体に独立して表示されてはなりません。

- Lines of characters in the body MUST be limited to 998 characters, and SHOULD be limited to 78 characters, excluding the CRLF.

- 本体内の文字の行は998文字に制限されなければならない、とCRLFを除いて、78文字に制限されるべきです。

Note: As was stated earlier, there are other standards documents, specifically the MIME documents [RFC2045, RFC2046, RFC2048, RFC2049] that extend this standard to allow for different sorts of message bodies. Again, these mechanisms are beyond the scope of this document.


3. Syntax
3.1. Introduction
3.1. 前書き

The syntax as given in this section defines the legal syntax of Internet messages. Messages that are conformant to this standard MUST conform to the syntax in this section. If there are options in this section where one option SHOULD be generated, that is indicated either in the prose or in a comment next to the syntax.

このセクションで与えられるような構文は、インターネットメッセージの法的な構文を定義します。この規格に準拠しているメッセージは、このセクションの構文に従わなければなりません。 1つのオプションは生成されるべきで、このセクションのオプションがある場合は、それが散文で、または次の構文にコメントのいずれかで示されています。

For the defined expressions, a short description of the syntax and use is given, followed by the syntax in ABNF, followed by a semantic analysis. Primitive tokens that are used but otherwise unspecified come from [RFC2234].


In some of the definitions, there will be nonterminals whose names start with "obs-". These "obs-" elements refer to tokens defined in the obsolete syntax in section 4. In all cases, these productions are to be ignored for the purposes of generating legal Internet messages and MUST NOT be used as part of such a message. However, when interpreting messages, these tokens MUST be honored as part of the legal syntax. In this sense, section 3 defines a grammar for generation of messages, with "obs-" elements that are to be ignored, while section 4 adds grammar for interpretation of messages.


3.2. Lexical Tokens
3.2. 字句

The following rules are used to define an underlying lexical analyzer, which feeds tokens to the higher-level parsers. This section defines the tokens used in structured header field bodies.


Note: Readers of this standard need to pay special attention to how these lexical tokens are used in both the lower-level and higher-level syntax later in the document. Particularly, the white space tokens and the comment tokens defined in section 3.2.3 get used in the lower-level tokens defined here, and those lower-level tokens are in turn used as parts of the higher-level tokens defined later. Therefore, the white space and comments may be allowed in the higher-level tokens even though they may not explicitly appear in a particular definition.


3.2.1. Primitive Tokens
3.2.1. プリミティブトークン

The following are primitive tokens referred to elsewhere in this standard, but not otherwise defined in [RFC2234]. Some of them will not appear anywhere else in the syntax, but they are convenient to refer to in other parts of this document.


Note: The "specials" below are just such an example. Though the specials token does not appear anywhere else in this standard, it is useful for implementers who use tools that lexically analyze messages. Each of the characters in specials can be used to indicate a tokenization point in lexical analysis.


NO-WS-CTL = %d1-8 / ; US-ASCII control characters %d11 / ; that do not include the %d12 / ; carriage return, line feed, %d14-31 / ; and white space characters %d127

NO - WS-CTL =%d1-8 /。 US-ASCIIの制御文字%D11 /。それは、%D12を/含まれていません。キャリッジリターン、改行、%のd14-31 /。そして、空白文字%D127

text = %d1-9 / ; Characters excluding CR and LF %d11 / %d12 / %d14-127 / obs-text

テキスト=%d1-9 /。 CRやLF%D11 / D12%/%d14-127 / OBSテキストを除く文字

specials = "(" / ")" / ; Special characters used in "<" / ">" / ; other parts of the syntax "[" / "]" / ":" / ";" / "@" / "\" / "," / "." / DQUOTE

スペシャル= "(" / ")" /;で使用される特殊文字 "<" / ">" /;シンタックスの他の部分 "[" / "]" / ":" / ";" / "@" / "\" / "" / "" / DQUOTE

No special semantics are attached to these tokens. They are simply single characters.


3.2.2. Quoted characters
3.2.2. 引用符で囲まれた文字

Some characters are reserved for special interpretation, such as delimiting lexical tokens. To permit use of these characters as uninterpreted data, a quoting mechanism is provided.


quoted-pair = ("\" text) / obs-qp

引用されたペア=( "\" テキスト)/ OBS-QP

Where any quoted-pair appears, it is to be interpreted as the text character alone. That is to say, the "\" character that appears as part of a quoted-pair is semantically "invisible".


Note: The "\" character may appear in a message where it is not part of a quoted-pair. A "\" character that does not appear in a quoted-pair is not semantically invisible. The only places in this standard where quoted-pair currently appears are ccontent, qcontent, dcontent, no-fold-quote, and no-fold-literal.


3.2.3. Folding white space and comments
3.2.3. 空白とコメントを折りたたみ

White space characters, including white space used in folding (described in section 2.2.3), may appear between many elements in header field bodies. Also, strings of characters that are treated as comments may be included in structured field bodies as characters enclosed in parentheses. The following defines the folding white space (FWS) and comment constructs.


Strings of characters enclosed in parentheses are considered comments so long as they do not appear within a "quoted-string", as defined in section 3.2.5. Comments may nest.


There are several places in this standard where comments and FWS may be freely inserted. To accommodate that syntax, an additional token for "CFWS" is defined for places where comments and/or FWS can occur. However, where CFWS occurs in this standard, it MUST NOT be inserted in such a way that any line of a folded header field is made up entirely of WSP characters and nothing else.

コメントやFWSを自由に挿入することができる。この標準でいくつかの場所があります。その構文に対応するために、「CFWS」のための追加のトークンは、コメントおよび/またはFWSが起こることができる場所のために定義されています。 CFWSは、この規格に発生する場所しかし、それは折り畳まれたヘッダフィールドの任意の行がWSP文字と何もないのみで構成され、このような方法で挿入されてはなりません。

FWS = ([*WSP CRLF] 1*WSP) / ; Folding white space obs-FWS

FWS =([* WSP CRLF] 1 * WSP)/。折りたたみ空白OBS-FWS

ctext = NO-WS-CTL / ; Non white space controls

CTEXT = NO - WS-CTL /。非ホワイトスペースコントロール

                        %d33-39 /       ; The rest of the US-ASCII
                        %d42-91 /       ;  characters not including "(",
                        %d93-126        ;  ")", or "\"

ccontent = ctext / quoted-pair / comment


comment = "(" *([FWS] ccontent) [FWS] ")"

komment = "(" *([FOS] skontent)FOS] ")"

CFWS = *([FWS] comment) (([FWS] comment) / FWS)

SFOS = *([FOS] komment)((FOS] komment)/ FOS)

Throughout this standard, where FWS (the folding white space token) appears, it indicates a place where header folding, as discussed in section 2.2.3, may take place. Wherever header folding appears in a message (that is, a header field body containing a CRLF followed by any WSP), header unfolding (removal of the CRLF) is performed before any further lexical analysis is performed on that header field according to this standard. That is to say, any CRLF that appears in FWS is semantically "invisible."


A comment is normally used in a structured field body to provide some human readable informational text. Since a comment is allowed to contain FWS, folding is permitted within the comment. Also note that since quoted-pair is allowed in a comment, the parentheses and backslash characters may appear in a comment so long as they appear as a quoted-pair. Semantically, the enclosing parentheses are not part of the comment; the comment is what is contained between the two parentheses. As stated earlier, the "\" in any quoted-pair and the CRLF in any FWS that appears within the comment are semantically "invisible" and therefore not part of the comment either.


Runs of FWS, comment or CFWS that occur between lexical tokens in a structured field header are semantically interpreted as a single space character.


3.2.4. Atom
3.2.4. 原子

Several productions in structured header field bodies are simply strings of certain basic characters. Such productions are called atoms.


Some of the structured header field bodies also allow the period character (".", ASCII value 46) within runs of atext. An additional "dot-atom" token is defined for those purposes.


atext = ALPHA / DIGIT / ; Any character except controls, "!" / "#" / ; SP, and specials. "$" / "%" / ; Used for atoms "&" / "'" / "*" / "+" / "-" / "/" / "=" / "?" / "^" / "_" / "`" / "{" / "|" / "}" / "~"

atext = ALPHA / DIGIT /。コントロール以外の任意の文字、「!」 / "#" /; SP、およびスペシャル。 "$" / "%" /;原子のために使用されます "&" / "'" / "*" / "+" / " - " / "/" / "=" / "?" / "^" / "_" / "`"/ "{"/ "|" / "}" / "〜"

atom = [CFWS] 1*atext [CFWS]

原子= [CFWS] 1 * [CFWS] atext

dot-atom = [CFWS] dot-atom-text [CFWS]

ドット原子= [CFWS]ドット原子テキスト[CFWS]

dot-atom-text = 1*atext *("." 1*atext)

ドット原子テキスト= 1 * atext *( "" 1 * atext)

Both atom and dot-atom are interpreted as a single unit, comprised of the string of characters that make it up. Semantically, the optional comments and FWS surrounding the rest of the characters are not part of the atom; the atom is only the run of atext characters in an atom, or the atext and "." characters in a dot-atom.


3.2.5. Quoted strings
3.2.5. 引用符で囲まれた文字列

Strings of characters that include characters other than those allowed in atoms may be represented in a quoted string format, where the characters are surrounded by quote (DQUOTE, ASCII value 34) characters.


qtext = NO-WS-CTL / ; Non white space controls

qtext = NO - WS-CTL /。非ホワイトスペースコントロール

                        %d33 /          ; The rest of the US-ASCII
                        %d35-91 /       ;  characters not including "\"
                        %d93-126        ;  or the quote character

qcontent = qtext / quoted-pair

qcontent = qtext /引用されたペア

quoted-string = [CFWS] DQUOTE *([FWS] qcontent) [FWS] DQUOTE [CFWS]

引用符で囲まれた文字列= [CFWS] DQUOTE×([FWS] qcontent)FWS] DQUOTE [CFWS]

A quoted-string is treated as a unit. That is, quoted-string is identical to atom, semantically. Since a quoted-string is allowed to contain FWS, folding is permitted. Also note that since quoted-pair is allowed in a quoted-string, the quote and backslash characters may appear in a quoted-string so long as they appear as a quoted-pair.


Semantically, neither the optional CFWS outside of the quote characters nor the quote characters themselves are part of the quoted-string; the quoted-string is what is contained between the two quote characters. As stated earlier, the "\" in any quoted-pair and the CRLF in any FWS/CFWS that appears within the quoted-string are semantically "invisible" and therefore not part of the quoted-string either.

意味的に、引用符の外のオプションのCFWSも引用符文字でもない自身が引用符で囲まれた文字列の一部です。引用符で囲まれた文字列は、2重引用符の間に含まれるものです。先に述べたように、任意の引用されたペアで「\」と引用符で囲まれた文字列の中に表示される任意のFWS / CFWSにおけるCRLFは意味的に「目に見えない」とのいずれか引用符で囲まれた文字列のため、一部ではありません。

3.2.6. Miscellaneous tokens
3.2.6. その他のトークン

Three additional tokens are defined, word and phrase for combinations of atoms and/or quoted-strings, and unstructured for use in unstructured header fields and in some places within structured header fields.


word = atom / quoted-string


phrase = 1*word / obs-phrase utext = NO-WS-CTL / ; Non white space controls %d33-126 / ; The rest of US-ASCII obs-utext

フレーズ= 1 *単語/ OBS-フレーズのutext = NO-WS、CTL /;非空白は/%のd33-126を制御します。 US-ASCIIのOBS-のutextの残りの部分

unstructured = *([FWS] utext) [FWS]

構造化されていない= *([FWS]のutext)FWS]

3.3. Date and Time Specification
3.3. 日付と時刻の指定

Date and time occur in several header fields. This section specifies the syntax for a full date and time specification. Though folding white space is permitted throughout the date-time specification, it is RECOMMENDED that a single space be used in each place that FWS appears (whether it is required or optional); some older implementations may not interpret other occurrences of folding white space correctly.


date-time = [ day-of-week "," ] date FWS time [CFWS]

日時= [曜日「」]日付FWS時間[CFWS]

day-of-week = ([FWS] day-name) / obs-day-of-week

曜日=([FWS]日-名)/ OBS-曜日

day-name = "Mon" / "Tue" / "Wed" / "Thu" / "Fri" / "Sat" / "Sun"


date = day month year


year = 4*DIGIT / obs-year

年= 4 * DIGIT / OBS年

month = (FWS month-name FWS) / obs-month

月=(FWS月-名FWS)/ OBS-月

month-name = "Jan" / "Feb" / "Mar" / "Apr" / "May" / "Jun" / "Jul" / "Aug" / "Sep" / "Oct" / "Nov" / "Dec"


day = ([FWS] 1*2DIGIT) / obs-day


time = time-of-day FWS zone


time-of-day = hour ":" minute [ ":" second ]


hour = 2DIGIT / obs-hour

時間= 2DIGIT / OBS時間対応

minute = 2DIGIT / obs-minute

分= 2DIGIT / OBS分

second = 2DIGIT / obs-second

第二= 2DIGIT / OBS秒

zone = (( "+" / "-" ) 4DIGIT) / obs-zone

ゾーン=(( "+" / " - ")4桁)/ OBSゾーン

The day is the numeric day of the month. The year is any numeric year 1900 or later.


The time-of-day specifies the number of hours, minutes, and optionally seconds since midnight of the date indicated.


The date and time-of-day SHOULD express local time.


The zone specifies the offset from Coordinated Universal Time (UTC, formerly referred to as "Greenwich Mean Time") that the date and time-of-day represent. The "+" or "-" indicates whether the time-of-day is ahead of (i.e., east of) or behind (i.e., west of) Universal Time. The first two digits indicate the number of hours difference from Universal Time, and the last two digits indicate the number of minutes difference from Universal Time. (Hence, +hhmm means +(hh * 60 + mm) minutes, and -hhmm means -(hh * 60 + mm) minutes). The form "+0000" SHOULD be used to indicate a time zone at Universal Time. Though "-0000" also indicates Universal Time, it is used to indicate that the time was generated on a system that may be in a local time zone other than Universal Time and therefore indicates that the date-time contains no information about the local time zone.

ゾーンは、日付と時刻を表していることを協定世界時(以前は「グリニッジ標準時」と呼ばれるUTC)からのオフセットを指定します。 「+」または「 - 」の時刻が先の(即ち、東)または後ろ世界時(のすなわち、西)であるかどうかを示します。最初の2桁は世界時からの時間差の数を示し、最後の2桁は世界時からの分差の数を示しています。 (したがって、+ HHMM手段+(HH * 60 + mm)の分、及び-hhmm手段 - (HH * 60 +ミリメートル)分)。フォーム「0000」は世界時の時間帯を示すために使用されるべきです。 「-0000」はまた、ユニバーサル・タイムを示しますが、時間が世界時以外のローカルタイムゾーンであることができるシステムで生成し、それゆえ日時は現地時間に関する情報が含まれていないことを示したことを示すために使用されますゾーン。

A date-time specification MUST be semantically valid. That is, the day-of-the-week (if included) MUST be the day implied by the date, the numeric day-of-month MUST be between 1 and the number of days allowed for the specified month (in the specified year), the time-of-day MUST be in the range 00:00:00 through 23:59:60 (the number of seconds allowing for a leap second; see [STD12]), and the zone MUST be within the range -9959 through +9959.

日時指定は意味的に有効である必要があります。 (含まれている場合)これは、数値日の-月は指定された年で1と指定された月に許可される日数(の間である必要があり、日によって暗黙の日でなければならない、曜日です)、時刻は、(秒数が第2の跳躍を可能23:59:60までの範囲午後12時00分00秒でなければならない。[STD12]参照)、ゾーンの範囲内になければなりません - 9959て9959。

3.4. Address Specification
3.4. アドレスの指定

Addresses occur in several message header fields to indicate senders and recipients of messages. An address may either be an individual mailbox, or a group of mailboxes.


address = mailbox / group


mailbox = name-addr / addr-spec

メールボックス=名前-addrに/ addrのスペック

name-addr = [display-name] angle-addr

名前-ADDR = [表示名]角度-ADDR

angle-addr = [CFWS] "<" addr-spec ">" [CFWS] / obs-angle-addr

角度-ADDR = [CFWS] "<" ADDRスペック ">" [CFWS] / OBS角-ADDR

group = display-name ":" [mailbox-list / CFWS] ";" [CFWS]

グループ=表示名「:」[メールボックスリスト/ CFWS]「;」 [CFWS]

display-name = phrase


mailbox-list = (mailbox *("," mailbox)) / obs-mbox-list

メールボックスリスト=(メールボックス*( "" メールボックス))/ OBS-MBOX-リスト

address-list = (address *("," address)) / obs-addr-list

アドレスリスト=(アドレス*( "" アドレス))/ OBS-addrにリスト

A mailbox receives mail. It is a conceptual entity which does not necessarily pertain to file storage. For example, some sites may choose to print mail on a printer and deliver the output to the addressee's desk. Normally, a mailbox is comprised of two parts: (1) an optional display name that indicates the name of the recipient (which could be a person or a system) that could be displayed to the user of a mail application, and (2) an addr-spec address enclosed in angle brackets ("<" and ">"). There is also an alternate simple form of a mailbox where the addr-spec address appears alone, without the recipient's name or the angle brackets. The Internet addr-spec address is described in section 3.4.1.

メールボックスは、メールを受信します。それは必ずしもストレージをファイルに関係しない概念的な実体です。例えば、いくつかのサイトには、プリンターにメールを印刷して、宛先の机に出力を提供することもできます。通常、メールボックスは、2つの部分から構成されている:(1)メールアプリケーションのユーザに表示することができる(人またはシステムとすることができる)受信者の名前を示し、そして任意の表示名(2)角括弧(「<」と「>」)で囲まれたADDRスペックアドレス。 addrスペックアドレスが受信者の名前や角括弧なしで単独で表示されるメールボックスの代わりのシンプルな形もあります。インターネットのaddrスペックアドレスはセクション3.4.1に記載されています。

Note: Some legacy implementations used the simple form where the addr-spec appears without the angle brackets, but included the name of the recipient in parentheses as a comment following the addr-spec. Since the meaning of the information in a comment is unspecified, implementations SHOULD use the full name-addr form of the mailbox, instead of the legacy form, to specify the display name associated with a mailbox. Also, because some legacy implementations interpret the comment, comments generally SHOULD NOT be used in address fields to avoid confusing such implementations.


When it is desirable to treat several mailboxes as a single unit (i.e., in a distribution list), the group construct can be used. The group construct allows the sender to indicate a named group of recipients. This is done by giving a display name for the group, followed by a colon, followed by a comma separated list of any number of mailboxes (including zero and one), and ending with a semicolon. Because the list of mailboxes can be empty, using the group construct is also a simple way to communicate to recipients that the message was sent to one or more named sets of recipients, without actually providing the individual mailbox address for each of those recipients.


3.4.1. Addr-spec specification
3.4.1. ADDRスペック仕様

An addr-spec is a specific Internet identifier that contains a locally interpreted string followed by the at-sign character ("@", ASCII value 64) followed by an Internet domain. The locally interpreted string is either a quoted-string or a dot-atom. If the string can be represented as a dot-atom (that is, it contains no characters other than atext characters or "." surrounded by atext characters), then the dot-atom form SHOULD be used and the quoted-string form SHOULD NOT be used. Comments and folding white space SHOULD NOT be used around the "@" in the addr-spec.


addr-spec = local-part "@" domain


local-part = dot-atom / quoted-string / obs-local-part

ローカル・パート=ドット原子/引用符で囲まれた文字列/ OBS-ローカル部分

domain = dot-atom / domain-literal / obs-domain

ドメイン=ドット原子/ドメインリテラル/ OBS-ドメイン

domain-literal = [CFWS] "[" *([FWS] dcontent) [FWS] "]" [CFWS]

ドメインリテラル= [SFOS] "[" *([FOS] dkontent)FOS] "]" [SFOS]

dcontent = dtext / quoted-pair


dtext = NO-WS-CTL / ; Non white space controls

dtext = NO - WS-CTL /。非ホワイトスペースコントロール

                        %d33-90 /       ; The rest of the US-ASCII
                        %d94-126        ;  characters not including "[",
                                        ;  "]", or "\"

The domain portion identifies the point to which the mail is delivered. In the dot-atom form, this is interpreted as an Internet domain name (either a host name or a mail exchanger name) as described in [STD3, STD13, STD14]. In the domain-literal form, the domain is interpreted as the literal Internet address of the particular host. In both cases, how addressing is used and how messages are transported to a particular host is covered in the mail transport document [RFC2821]. These mechanisms are outside of the scope of this document.


The local-part portion is a domain dependent string. In addresses, it is simply interpreted on the particular host as a name of a particular mailbox.


3.5 Overall message syntax

A message consists of header fields, optionally followed by a message body. Lines in a message MUST be a maximum of 998 characters excluding the CRLF, but it is RECOMMENDED that lines be limited to 78 characters excluding the CRLF. (See section 2.1.1 for explanation.) In a message body, though all of the characters listed in the text rule MAY be used, the use of US-ASCII control characters (values 1 through 8, 11, 12, and 14 through 31) is discouraged since their interpretation by receivers for display is not guaranteed.

メッセージは、必要に応じて、メッセージ本体に続くヘッダフィールド、から構成されています。メッセージの行は、CRLFを除いて998文字以内でなければならないが、ラインはCRLFを除いた78文字に制限されることが推奨されます。 (説明についてはセクション2.1.1を参照。)メッセージ本文に、テキスト規則に記載されているすべての文字を使用することができるが、US-ASCII制御文字を使用する(値1〜8、11、12、および14〜表示のための受信機によってその解釈が保証されないので、31)が推奨されていません。

message = (fields / obs-fields) [CRLF body]

メッセージ=(フィールド/ OBSフィールド)CRLF体]

body = *(*998text CRLF) *998text

ボディ= *(* 998text CRLF)* 998text

The header fields carry most of the semantic information and are defined in section 3.6. The body is simply a series of lines of text which are uninterpreted for the purposes of this standard.


3.6. Field definitions
3.6. フィールド定義

The header fields of a message are defined here. All header fields have the same general syntactic structure: A field name, followed by a colon, followed by the field body. The specific syntax for each header field is defined in the subsequent sections.


Note: In the ABNF syntax for each field in subsequent sections, each field name is followed by the required colon. However, for brevity sometimes the colon is not referred to in the textual description of the syntax. It is, nonetheless, required.


It is important to note that the header fields are not guaranteed to be in a particular order. They may appear in any order, and they have been known to be reordered occasionally when transported over the Internet. However, for the purposes of this standard, header fields SHOULD NOT be reordered when a message is transported or transformed. More importantly, the trace header fields and resent header fields MUST NOT be reordered, and SHOULD be kept in blocks prepended to the message. See sections 3.6.6 and 3.6.7 for more information.


The only required header fields are the origination date field and the originator address field(s). All other header fields are syntactically optional. More information is contained in the table following this definition.


fields = *(trace *(resent-date / resent-from / resent-sender / resent-to / resent-cc / resent-bcc / resent-msg-id)) *(orig-date / from / sender / reply-to / to / cc / bcc / message-id / in-reply-to / references / subject / comments / keywords / optional-field)

フィールド= *(トレース*(再送日付/再送-から/再送、送信者/再送対/再送-CC /再送-BCC /再送-MSG-ID))*(ORIG-日付/送信者/ reply- /から)/ TO / CC / BCC /メッセージID /イン返信する/参照/主題/コメント/キーワード/オプションのフィールドに

The following table indicates limits on the number of times each field may occur in a message header as well as any special limitations on the use of those fields. An asterisk next to a value in the minimum or maximum column indicates that a special restriction appears in the Notes column.


Field Min number Max number Notes


trace 0 unlimited Block prepended - see 3.6.7

トレース0無制限のブロックが先頭に追加 - 3.6.7を参照してください

resent-date 0* unlimited* One per block, required if other resent fields present - see 3.6.6

3.6.6を参照してください - 0に存在する他の再送フィールド場合に必要なブロックごとに1つ、*無制限*日付は憤慨します

resent-from 0 unlimited* One per block - see 3.6.6

再送-から無制限0 *ブロックごとに1つ - 3.6.6を参照してください

resent-sender 0* unlimited* One per block, MUST occur with multi-address resent-from - see 3.6.6

再送-差出人*無制限の0を*ブロックごとに1つ、マルチアドレス再送-からで発生しなければならない - 3.6.6を参照してください

resent-to 0 unlimited* One per block - see 3.6.6

再送-に無制限0 *ブロックごとに1つ - 3.6.6を参照してください

resent-cc 0 unlimited* One per block - see 3.6.6

再送-CC 0無制限*ブロックごとに1つ - 3.6.6を参照してください

resent-bcc 0 unlimited* One per block - see 3.6.6

再送-BCC無制限0 *ブロックごとに1つ - 3.6.6を参照してください

resent-msg-id 0 unlimited* One per block - see 3.6.6

再送-MSG-ID 0無制限*ブロックごとに1つ - 3.6.6を参照してください

orig-date 1 1

ORIG-日付1 1

from 1 1 See sender and 3.6.2 sender 0* 1 MUST occur with multi-address from - see 3.6.2

1つの1を参照の送信者および3.6.2送信者から0 * 1から、マルチアドレスで発生しなければならない - 3.6.2を参照してください

reply-to 0 1

返信-0 1

to 0 1

と 0 1

cc 0 1

CC 0 1

bcc 0 1

BCC 0 1

message-id 0* 1 SHOULD be present - see 3.6.4

メッセージID 0 * 1が存在する必要があります - 3.6.4を参照します

in-reply-to 0* 1 SHOULD occur in some replies - see 3.6.4

* 1 0への返信で、いくつかの回答で発生する必要があります - 3.6.4を参照してください

references 0* 1 SHOULD occur in some replies - see 3.6.4

リファレンス0 * 1は、いくつかの回答で発生する必要があります - 3.6.4を参照してください

subject 0 1

対象0 1

comments 0 unlimited


keywords 0 unlimited


optional-field 0 unlimited


The exact interpretation of each field is described in subsequent sections.


3.6.1. The origination date field
3.6.1. 発信日付フィールド

The origination date field consists of the field name "Date" followed by a date-time specification.


orig-date = "Date:" date-time CRLF

ORIG-日付= "日:" 日時CRLF

The origination date specifies the date and time at which the creator of the message indicated that the message was complete and ready to enter the mail delivery system. For instance, this might be the time that a user pushes the "send" or "submit" button in an application program. In any case, it is specifically not intended to convey the time that the message is actually transported, but rather the time at which the human or other creator of the message has put the message into its final form, ready for transport. (For example, a portable computer user who is not connected to a network might queue a message for delivery. The origination date is intended to contain the date and time that the user queued the message, not the time when the user connected to the network to send the message.)

発信日時は、メッセージの作成者は、メッセージが完了し、メール配信システムを入力する準備ができたことが示された日時を指定します。例えば、これは、ユーザがアプリケーション・プログラムで「送信」「送信」ボタンを押すか、時間があるかもしれません。いずれの場合においても、特に、メッセージが実際に輸送された時間ではなく、メッセージのヒトまたは他の作成者が輸送のための準備ができて、その最終的な形にメッセージを入れた時刻を伝えることを意図するものではありません。 (例えば、ネットワークに接続されていないポータブルコンピュータのユーザは、配信のためにメッセージをキューに入れるかもしれません。元の日付が、ユーザーがメッセージではなく、ユーザがネットワークに接続されている時間をキューに入れられた日付と時刻を含めることを意図していますメッセージを送信します。)

3.6.2. Originator fields
3.6.2. 発信元フィールド

The originator fields of a message consist of the from field, the sender field (when applicable), and optionally the reply-to field. The from field consists of the field name "From" and a comma-separated list of one or more mailbox specifications. If the from field contains more than one mailbox specification in the mailbox-list, then the sender field, containing the field name "Sender" and a single mailbox specification, MUST appear in the message. In either case, an optional reply-to field MAY also be included, which contains the field name "Reply-To" and a comma-separated list of one or more addresses.


from = "From:" mailbox-list CRLF


sender = "Sender:" mailbox CRLF


reply-to = "Reply-To:" address-list CRLF


The originator fields indicate the mailbox(es) of the source of the message. The "From:" field specifies the author(s) of the message, that is, the mailbox(es) of the person(s) or system(s) responsible for the writing of the message. The "Sender:" field specifies the mailbox of the agent responsible for the actual transmission of the message. For example, if a secretary were to send a message for another person, the mailbox of the secretary would appear in the "Sender:" field and the mailbox of the actual author would appear in the "From:" field. If the originator of the message can be indicated by a single mailbox and the author and transmitter are identical, the "Sender:" field SHOULD NOT be used. Otherwise, both fields SHOULD appear.

発信元フィールドは、メッセージの送信元のメールボックス(es)を示しています。 「から:」フィールドには、メッセージの作成者(複数可)を指定し、それは、人(複数可)またはメッセージの書き込みを担当するシステム(複数可)のメールボックス(複数可)です。 「送信者:」フィールドは、メッセージの実際の送信を担当するエージェントのメールボックスを指定します。秘書が別の人のためのメッセージを送信した場合例えば、秘書のメールボックスがに表示される「送信者:」フィールドと実際の著者のメールボックスは、「から:」に表示されますフィールド。メッセージの発信元は、単一のメールボックスで表示することができ、作者と送信機が同一である場合は、「送信者:」フィールドは使用されるべきではありません。それ以外の場合は、両方のフィールドが表示されます。

The originator fields also provide the information required when replying to a message. When the "Reply-To:" field is present, it indicates the mailbox(es) to which the author of the message suggests that replies be sent. In the absence of the "Reply-To:" field, replies SHOULD by default be sent to the mailbox(es) specified in the "From:" field unless otherwise specified by the person composing the reply.

発信元フィールドもメッセージに返信するときに必要な情報を提供します。 「返信先:」ときにフィールドが存在し、それはメッセージの作成者が応答を送信することを示唆しているメールボックス(複数可)に示しています。 「返信先:」がない場合には、フィールドに指定されたメールボックス(複数可)に送信され、デフォルトでSHOULDを返信「から:」そう返事を構成する人によって指定されない限り、フィールド。

In all cases, the "From:" field SHOULD NOT contain any mailbox that does not belong to the author(s) of the message. See also section 3.6.3 for more information on forming the destination addresses for a reply.


3.6.3. Destination address fields
3.6.3. 宛先アドレスフィールド

The destination fields of a message consist of three possible fields, each of the same form: The field name, which is either "To", "Cc", or "Bcc", followed by a comma-separated list of one or more addresses (either mailbox or group syntax).

メッセージの宛先フィールドは、次の3つのフィールド、同じ形式の各々から成る:フィールド名のいずれか「を」、1つ以上のアドレスのカンマ区切りリストが続き、「CC」、又は「のBcc」、 (メールボックスまたはグループの構文のいずれか)。

to = "To:" address-list CRLF


cc = "Cc:" address-list CRLF

CC = "CC:" アドレスリストCRLF

bcc = "Bcc:" (address-list / [CFWS]) CRLF

BCC = "のBcc:"(アドレスリスト/ [CFWS])CRLF

The destination fields specify the recipients of the message. Each destination field may have one or more addresses, and each of the addresses indicate the intended recipients of the message. The only difference between the three fields is how each is used.


The "To:" field contains the address(es) of the primary recipient(s) of the message.


The "Cc:" field (where the "Cc" means "Carbon Copy" in the sense of making a copy on a typewriter using carbon paper) contains the addresses of others who are to receive the message, though the content of the message may not be directed at them.


The "Bcc:" field (where the "Bcc" means "Blind Carbon Copy") contains addresses of recipients of the message whose addresses are not to be revealed to other recipients of the message. There are three ways in which the "Bcc:" field is used. In the first case, when a message containing a "Bcc:" field is prepared to be sent, the "Bcc:" line is removed even though all of the recipients (including those specified in the "Bcc:" field) are sent a copy of the message. In the second case, recipients specified in the "To:" and "Cc:" lines each are sent a copy of the message with the "Bcc:" line removed as above, but the recipients on the "Bcc:" line get a separate copy of the message containing a "Bcc:" line. (When there are multiple recipient addresses in the "Bcc:" field, some implementations actually send a separate copy of the message to each recipient with a "Bcc:" containing only the address of that particular recipient.) Finally, since a "Bcc:" field may contain no addresses, a "Bcc:" field can be sent without any addresses indicating to the recipients that blind copies were sent to someone. Which method to use with "Bcc:" fields is implementation dependent, but refer to the "Security Considerations" section of this document for a discussion of each.

「のBcc:」フィールド(「BCCが」「ブラインドカーボンコピー」を意味する)アドレスメッセージの他の受信者に明らかにされるべきではないメッセージの受信者のアドレスを含みます。フィールド使用されている:「のBcc」とは、3つの方法があります。 「のBcc:」フィールドは、送信されるように調製される含むメッセージを第一のケースでは、「Bccのに:」線も受信者の全ても除去する(で指定されたものを含む「のBcc:」フィールド)が送信されますメッセージのコピー。後者の場合、受信者はで指定された「:を」と「cc:」行は、それぞれのメッセージのコピーを送信している「のBcc:」ラインは、上記のように除去したが、上の受信者「のBcc:」は線得ます行:「のBcc」を含むメッセージの別のコピー。 (内の複数の受信者のアドレスがある場合、「BCCが:」「のBcc:」フィールド、いくつかの実装は、実際に各受信者にメッセージの別のコピーを送信する。その特定の受信者のアドレスのみを含む)最後に、「Bccのため:のBcc」フィールドには、何のアドレスが含まれないことがあり、 『:』フィールドには、ブラインドコピーを誰かに送信された受信者に示す任意のアドレスをせずに送信することができます。どちらで使用する方法「のBcc:」フィールドの実装に依存しているが、それぞれの議論のために、このドキュメントの「セキュリティに関する考慮事項」を参照してください。

When a message is a reply to another message, the mailboxes of the authors of the original message (the mailboxes in the "From:" field) or mailboxes specified in the "Reply-To:" field (if it exists) MAY appear in the "To:" field of the reply since these would normally be the primary recipients of the reply. If a reply is sent to a message that has destination fields, it is often desirable to send a copy of the reply to all of the recipients of the message, in addition to the author. When such a reply is formed, addresses in the "To:" and "Cc:" fields of the original message MAY appear in the "Cc:" field of the reply, since these are normally secondary recipients of the reply. If a "Bcc:" field is present in the original message, addresses in that field MAY appear in the "Bcc:" field of the reply, but SHOULD NOT appear in the "To:" or "Cc:" fields.


Note: Some mail applications have automatic reply commands that include the destination addresses of the original message in the destination addresses of the reply. How those reply commands behave is implementation dependent and is beyond the scope of this document. In particular, whether or not to include the original destination addresses when the original message had a "Reply-To:" field is not addressed here.


3.6.4. Identification fields
3.6.4. 識別フィールド

Though optional, every message SHOULD have a "Message-ID:" field. Furthermore, reply messages SHOULD have "In-Reply-To:" and "References:" fields as appropriate, as described below.


The "Message-ID:" field contains a single unique message identifier. The "References:" and "In-Reply-To:" field each contain one or more unique message identifiers, optionally separated by CFWS.

「メッセージID:」フィールドには、単一のユニークなメッセージ識別子が含まれています。 「参照:」および「イン返信先:」フィールドそれぞれは、任意CFWSで区切られた1つ以上の一意のメッセージ識別子を含みます。

The message identifier (msg-id) is similar in syntax to an angle-addr construct without the internal CFWS.


message-id = "Message-ID:" msg-id CRLF

メッセージID = "メッセージID:" MSG-ID CRLF

in-reply-to = "In-Reply-To:" 1*msg-id CRLF

1 * MSG-ID CRLF:= "で、返信先" - 応答対で

references = "References:" 1*msg-id CRLF

参照= "参考資料:" 1 *のMSG-ID CRLF

msg-id = [CFWS] "<" id-left "@" id-right ">" [CFWS]

MSG-ID = [CFWS] "<" ID-ID左から右 "@" ">" [CFWS]

id-left = dot-atom-text / no-fold-quote / obs-id-left

ID-左=ドット原子テキスト/ノー倍引用符/ OBS-ID-左

id-right = dot-atom-text / no-fold-literal / obs-id-right

ID-右=ドット原子テキスト/ノー倍リテラル/ OBS-ID-右

no-fold-quote = DQUOTE *(qtext / quoted-pair) DQUOTE no-fold-literal = "[" *(dtext / quoted-pair) "]"

ノー倍引用符= DQUOTE *(qtext /引用されたペア)ノー倍リテラル=「[」*(dtext /引用されたペアを)「]」DQUOTE

The "Message-ID:" field provides a unique message identifier that refers to a particular version of a particular message. The uniqueness of the message identifier is guaranteed by the host that generates it (see below). This message identifier is intended to be machine readable and not necessarily meaningful to humans. A message identifier pertains to exactly one instantiation of a particular message; subsequent revisions to the message each receive new message identifiers.


Note: There are many instances when messages are "changed", but those changes do not constitute a new instantiation of that message, and therefore the message would not get a new message identifier. For example, when messages are introduced into the transport system, they are often prepended with additional header fields such as trace fields (described in section 3.6.7) and resent fields (described in section 3.6.6). The addition of such header fields does not change the identity of the message and therefore the original "Message-ID:" field is retained. In all cases, it is the meaning that the sender of the message wishes to convey (i.e., whether this is the same message or a different message) that determines whether or not the "Message-ID:" field changes, not any particular syntactic difference that appears (or does not appear) in the message.


The "In-Reply-To:" and "References:" fields are used when creating a reply to a message. They hold the message identifier of the original message and the message identifiers of other messages (for example, in the case of a reply to a message which was itself a reply). The "In-Reply-To:" field may be used to identify the message (or messages) to which the new message is a reply, while the "References:" field may be used to identify a "thread" of conversation.


When creating a reply to a message, the "In-Reply-To:" and "References:" fields of the resultant message are constructed as follows:


The "In-Reply-To:" field will contain the contents of the "Message-ID:" field of the message to which this one is a reply (the "parent message"). If there is more than one parent message, then the "In-Reply-To:" field will contain the contents of all of the parents' "Message-ID:" fields. If there is no "Message-ID:" field in any of the parent messages, then the new message will have no "In-Reply-To:" field.

「イン返信-TO:」:これは、応答(「親メッセージ」)されたメッセージのフィールド「メッセージID」フィールドは、コンテンツを含むことになります。複数の親メッセージがある場合、「イン返信先:」:フィールドのフィールドには、両親の 『メッセージID』の全ての内容が含まれています。何の「メッセージID:」が存在しない場合は、次のフィールドフィールドは、親メッセージのいずれかで、その後、新しいメッセージは、「では、返信先」なしています。

The "References:" field will contain the contents of the parent's "References:" field (if any) followed by the contents of the parent's "Message-ID:" field (if any). If the parent message does not contain a "References:" field but does have an "In-Reply-To:" field containing a single message identifier, then the "References:" field will contain the contents of the parent's "In-Reply-To:" field followed by the contents of the parent's "Message-ID:" field (if any). If the parent has none of the "References:", "In-Reply-To:", or "Message-ID:" fields, then the new message will have no "References:" field.

「参考資料:」フィールド(もしあれば):親の「メッセージID」の内容が続くフィールド(もしあれば)フィールドは、親の「参考資料」の内容が含まれています。親メッセージは、「参考資料:」含まれていない場合は、フィールドをしかし持っている「イン返信先:」単一のメッセージ識別子を含むフィールド、そして「参考文献:」フィールドには、親の「イン返信の内容が含まれています-to:メッセージID」親の内容が続くフィールド 『:』フィールド(もしあれば)。親は「参考文献:」のどれを持っていない場合は、「では、返信先:」、または「メッセージID:」フィールドには、新しいメッセージはありません「参考文献:」必要がありますフィールドを。

Note: Some implementations parse the "References:" field to display the "thread of the discussion". These implementations assume that each new message is a reply to a single parent and hence that they can walk backwards through the "References:" field to find the parent of each message listed there. Therefore, trying to form a "References:" field for a reply that has multiple parents is discouraged and how to do so is not defined in this document.


The message identifier (msg-id) itself MUST be a globally unique identifier for a message. The generator of the message identifier MUST guarantee that the msg-id is unique. There are several algorithms that can be used to accomplish this. Since the msg-id has a similar syntax to angle-addr (identical except that comments and folding white space are not allowed), a good method is to put the domain name (or a domain literal IP address) of the host on which the message identifier was created on the right hand side of the "@", and put a combination of the current absolute date and time along with some other currently unique (perhaps sequential) identifier available on the system (for example, a process id number) on the left hand side. Using a date on the left hand side and a domain name or domain literal on the right hand side makes it possible to guarantee uniqueness since no two hosts use the same domain name or IP address at the same time. Though other algorithms will work, it is RECOMMENDED that the right hand side contain some domain identifier (either of the host itself or otherwise) such that the generator of the message identifier can guarantee the uniqueness of the left hand side within the scope of that domain.

メッセージ識別子(MSG-ID)自体は、メッセージのグローバルにユニークな識別子でなければなりません。メッセージ識別子のジェネレータは、MSG-IDが一意であることを保証しなければなりません。これを実現するために使用することができ、いくつかのアルゴリズムがあります。 MSG-idは(コメントや空白の折りたたみが許可されていないことを除いて同一である)角度-addrに似た構文を持っているので、良い方法は、ホストのドメイン名(またはドメインリテラルIPアドレス)を置くことである、その上にメッセージ識別子は、「@」の右側に作成され、システム上の他のいくつかの現在のユニークな(おそらくシーケンシャル)識別子と共に利用可能な現在の絶対日付と時刻の組み合わせを入れた(例えば、プロセスID番号)左側の。左側に日付を使用すると、何の2つのホストが同時に同じドメイン名またはIPアドレスを使用しないので、右側のリテラルのドメイン名またはドメインは、一意性を保証することが可能となります。他のアルゴリズムが動作するが、右手側は、メッセージ識別子のジェネレータは、そのドメインの範囲内で左側の一意性を保証することができるいくつかのドメイン識別子(ホスト自体または他の方法のいずれか)ように含有することが推奨されます。

Semantically, the angle bracket characters are not part of the msg-id; the msg-id is what is contained between the two angle bracket characters.

意味的に、アングルブラケット文字はMSG-IDの一部ではありません。 MSG-IDは、二つのアングルブラケット文字の間に含まれるものです。

3.6.5. Informational fields
3.6.5. 情報フィールド

The informational fields are all optional. The "Keywords:" field contains a comma-separated list of one or more words or quoted-strings. The "Subject:" and "Comments:" fields are unstructured fields as defined in section 2.2.1, and therefore may contain text or folding white space.

情報フィールドはすべてオプションです。 「キーワード:」フィールドには、1つ以上の単語または引用符で囲まれ、文字列のカンマ区切りのリストが含まれています。 「件名:」と「コメント:」フィールドはセクション2.2.1で定義された非構造化フィールドであるため、テキストや折りたたみ空白が含まれていてもよいです。

subject = "Subject:" unstructured CRLF


comments = "Comments:" unstructured CRLF


keywords = "Keywords:" phrase *("," phrase) CRLF

キーワード= "キーワード:" というフレーズ*( "" というフレーズ)CRLF

These three fields are intended to have only human-readable content with information about the message. The "Subject:" field is the most common and contains a short string identifying the topic of the message. When used in a reply, the field body MAY start with the string "Re: " (from the Latin "res", in the matter of) followed by the contents of the "Subject:" field body of the original message. If this is done, only one instance of the literal string "Re: " ought to be used since use of other strings or more than one instance can lead to undesirable consequences. The "Comments:" field contains any additional comments on the text of the body of the message. The "Keywords:" field contains a comma-separated list of important words and phrases that might be useful for the recipient.

これらの三つのフィールドは、メッセージに関する情報を有する唯一の人間が読めるコンテンツを有することが意図されています。 「件名:」フィールドには、最も一般的であり、メッセージの話題を識別する短い文字列が含まれています。 (の問題ではラテン語「RES」から)「件名:」の内容に続いて、元のメッセージのフィールドボディ:返信で使用する場合、フィールドボディは「再」の文字列で始まるかもしれません。これは文字列リテラルの行われ、唯一のインスタンスである場合は、「再:」他の文字列の使用または複数のインスタンスから使用されるべきであることは望ましくない結果につながることができます。 「コメント:」フィールドには、メッセージの本文のテキスト上の任意の追加のコメントが含まれています。 「キーワード:」フィールドは、受信者のために役に立つかもしれない重要な単語やフレーズをカンマで区切ったリストが含まれています。

3.6.6. Resent fields
3.6.6. 再送フィールド

Resent fields SHOULD be added to any message that is reintroduced by a user into the transport system. A separate set of resent fields SHOULD be added each time this is done. All of the resent fields corresponding to a particular resending of the message SHOULD be together. Each new set of resent fields is prepended to the message; that is, the most recent set of resent fields appear earlier in the message. No other fields in the message are changed when resent fields are added.


Each of the resent fields corresponds to a particular field elsewhere in the syntax. For instance, the "Resent-Date:" field corresponds to the "Date:" field and the "Resent-To:" field corresponds to the "To:" field. In each case, the syntax for the field body is identical to the syntax given previously for the corresponding field.


When resent fields are used, the "Resent-From:" and "Resent-Date:" fields MUST be sent. The "Resent-Message-ID:" field SHOULD be sent. "Resent-Sender:" SHOULD NOT be used if "Resent-Sender:" would be identical to "Resent-From:".

再送フィールドが使用されている場合は、「再送-から:」と「憤慨し-日:」フィールドが送らなければなりません。 「憤慨し、メッセージID:」フィールドが送られるべきです。 「憤慨し、送信者:」場合に使用されるべきではない「憤慨し、送信者:」と同一である「のResent-から:」。

resent-date = "Resent-Date:" date-time CRLF


resent-from = "Resent-From:" mailbox-list CRLF

再送-から= "のResent-から:" メールボックスリストCRLF

resent-sender = "Resent-Sender:" mailbox CRLF


resent-to = "Resent-To:" address-list CRLF


resent-cc = "Resent-Cc:" address-list CRLF

再送-CC = "憤慨し-CC:" アドレスリストCRLF

resent-bcc = "Resent-Bcc:" (address-list / [CFWS]) CRLF

再送-BCC = "憤慨-BCC:"(アドレスリスト/ [CFWS])CRLF

resent-msg-id = "Resent-Message-ID:" msg-id CRLF

再送-MSG-ID = "憤慨、メッセージID:" MSG-ID CRLF

Resent fields are used to identify a message as having been reintroduced into the transport system by a user. The purpose of using resent fields is to have the message appear to the final recipient as if it were sent directly by the original sender, with all of the original fields remaining the same. Each set of resent fields correspond to a particular resending event. That is, if a message is resent multiple times, each set of resent fields gives identifying information for each individual time. Resent fields are strictly informational. They MUST NOT be used in the normal processing of replies or other such automatic actions on messages.


Note: Reintroducing a message into the transport system and using resent fields is a different operation from "forwarding". "Forwarding" has two meanings: One sense of forwarding is that a mail reading program can be told by a user to forward a copy of a message to another person, making the forwarded message the body of the new message. A forwarded message in this sense does not appear to have come from the original sender, but is an entirely new message from the forwarder of the message. On the other hand, forwarding is also used to mean when a mail transport program gets a message and forwards it on to a different destination for final delivery. Resent header fields are not intended for use with either type of forwarding.

注:輸送システムにメッセージ再導入し、再送フィールドを使用して「転送」とは異なる動作です。 「転送」は、2つの意味があります。転送の一つのセンスは、メールの読み取りプログラムが転送されたメッセージの新しいメッセージのボディを作り、他の人にメッセージのコピーを転送するために、ユーザによって語らすることができるということです。この意味で転送されたメッセージは、元の送信者から来ているように見えますが、メッセージの転送者から全く新しいメッセージではありません。一方、転送はまた、メール転送プログラムは、メッセージを取得し、最終的な送達のための別の宛先にそれを転送するときに意味するために使用されます。再送ヘッダフィールドは、転送のいずれのタイプで使用するために意図されていません。

The resent originator fields indicate the mailbox of the person(s) or system(s) that resent the message. As with the regular originator fields, there are two forms: a simple "Resent-From:" form which contains the mailbox of the individual doing the resending, and the more complex form, when one individual (identified in the "Resent-Sender:" field) resends a message on behalf of one or more others (identified in the "Resent-From:" field).

再送発信元フィールドはメッセージを再送信者(複数可)または装置(複数可)のメールボックスを示します。シンプルな「憤慨し-から:」再送を行う個々のメールボックスを含むフォーム、およびより複雑なフォーム、とき「憤慨し、送信者に識別される1つの個々の(通常の発信元フィールドと同じように、2つの形式があります。 『フィールド):憤慨し-から」フィールド)で同定された1つのまたは複数の他の(に代わってメッセージを再送します』。

Note: When replying to a resent message, replies behave just as they would with any other message, using the original "From:",


"Reply-To:", "Message-ID:", and other fields. The resent fields are only informational and MUST NOT be used in the normal processing of replies.


The "Resent-Date:" indicates the date and time at which the resent message is dispatched by the resender of the message. Like the "Date:" field, it is not the date and time that the message was actually transported.

「憤慨し-日:」再送メッセージがメッセージのリセンダによって派遣された日時を示します。 「日付:」のようにフィールドには、メッセージが実際に運ばれた日時ではありません。

The "Resent-To:", "Resent-Cc:", and "Resent-Bcc:" fields function identically to the "To:", "Cc:", and "Bcc:" fields respectively, except that they indicate the recipients of the resent message, not the recipients of the original message.

"憤慨し-TO:"、 "憤慨し-CC:"、および "憤慨し-のBcc:" フィールドは "宛先:" と同じに機能し、 "CC:"、および "Bccの:" 彼らは示していることを除いて、それぞれの分野、再送メッセージの受信者、元のメッセージの受信者ではありません。

The "Resent-Message-ID:" field provides a unique identifier for the resent message.


3.6.7. Trace fields
3.6.7. トレースフィールド

The trace fields are a group of header fields consisting of an optional "Return-Path:" field, and one or more "Received:" fields. The "Return-Path:" header field contains a pair of angle brackets that enclose an optional addr-spec. The "Received:" field contains a (possibly empty) list of name/value pairs followed by a semicolon and a date-time specification. The first item of the name/value pair is defined by item-name, and the second item is either an addr-spec, an atom, a domain, or a msg-id. Further restrictions may be applied to the syntax of the trace fields by standards that provide for their use, such as [RFC2821].

「受信:」フィールド、および1つまたは複数:「リターンパス」フィールドトレースフィールドは、オプションからなるヘッダフィールドのグループです。 「リターンパスを:」ヘッダフィールドは、オプションのADDR仕様を囲む角括弧の対を含んでいます。 「受信:」フィールドには、セミコロンと、日付・時間指定が続く名前/値ペアの(おそらく空の)リストが含まれています。名前/値ペアの最初の項目は、項目名によって定義され、2番目の項目は、ADDR仕様、原子、ドメイン、又はMSG-IDのいずれかです。さらなる制限は、[RFC2821]として、その使用を提供する規格でトレースフィールドの構文にも適用することができます。

trace = [return] 1*received

受信トレース= [リターン] 1 *

return = "Return-Path:" path CRLF


path = ([CFWS] "<" ([CFWS] / addr-spec) ">" [CFWS]) / obs-path

パス=([CFWS] "<"([CFWS] / ADDR-SPEC) ">" [CFWS])/ OBSパス

received = "Received:" name-val-list ";" date-time CRLF

";" 名前-VAL-リスト:= "受信" 受信日時CRLF

name-val-list = [CFWS] [name-val-pair *(CFWS name-val-pair)]

名前-VAL-リスト= [CFWS] [名-VAL-ペア*(CFWS名-VAL-ペア)]

name-val-pair = item-name CFWS item-value


item-name = ALPHA *(["-"] (ALPHA / DIGIT))

項目名=アルファ*([ " - "](ALPHA / DIGIT))

item-value = 1*angle-addr / addr-spec / atom / domain / msg-id

項目値= 1 *角度-ADDR / ADDRスペック/原子/ドメイン/ MSG-ID

A full discussion of the Internet mail use of trace fields is contained in [RFC2821]. For the purposes of this standard, the trace fields are strictly informational, and any formal interpretation of them is outside of the scope of this document.


3.6.8. Optional fields
3.6.8. オプションのフィールド

Fields may appear in messages that are otherwise unspecified in this standard. They MUST conform to the syntax of an optional-field. This is a field name, made up of the printable US-ASCII characters except SP and colon, followed by a colon, followed by any text which conforms to unstructured.


The field names of any optional-field MUST NOT be identical to any field name specified elsewhere in this standard.


optional-field = field-name ":" unstructured CRLF


field-name = 1*ftext

フィールド名= 1 *のFTEXT

ftext = %d33-57 / ; Any character except %d59-126 ; controls, SP, and ; ":".

FTEXT =%d33-57 /。 %のd59-126を除く任意の文字。コントロール、SP、および; ":"。

For the purposes of this standard, any optional field is uninterpreted.


4. Obsolete Syntax

Earlier versions of this standard allowed for different (usually more liberal) syntax than is allowed in this version. Also, there have been syntactic elements used in messages on the Internet whose interpretation have never been documented. Though some of these syntactic forms MUST NOT be generated according to the grammar in section 3, they MUST be accepted and parsed by a conformant receiver. This section documents many of these syntactic elements. Taking the grammar in section 3 and adding the definitions presented in this section will result in the grammar to use for interpretation of messages.


Note: This section identifies syntactic forms that any implementation MUST reasonably interpret. However, there are certainly Internet messages which do not conform to even the additional syntax given in this section. The fact that a particular form does not appear in any section of this document is not justification for computer programs to crash or for malformed data to be irretrievably lost by any implementation. To repeat an example, though this document requires lines in messages to be no longer than 998 characters, silently discarding the 999th and subsequent characters in a line without warning would still be bad behavior for an implementation. It is up to the implementation to deal with messages robustly.


One important difference between the obsolete (interpreting) and the current (generating) syntax is that in structured header field bodies (i.e., between the colon and the CRLF of any structured header field), white space characters, including folding white space, and comments can be freely inserted between any syntactic tokens. This allows many complex forms that have proven difficult for some implementations to parse.


Another key difference between the obsolete and the current syntax is that the rule in section 3.2.3 regarding lines composed entirely of white space in comments and folding white space does not apply. See the discussion of folding white space in section 4.2 below.


Finally, certain characters that were formerly allowed in messages appear in this section. The NUL character (ASCII value 0) was once allowed, but is no longer for compatibility reasons. CR and LF were allowed to appear in messages other than as CRLF; this use is also shown here.

最後に、以前のメッセージで許可された特定の文字は、このセクションに表示されます。 NUL文字(ASCII値0)が一度許されませんが、互換性のために、もはやありました。 CRとLFをCRLFとして以外のメッセージに表示させました。この使用は、また、ここに示されています。

Other differences in syntax and semantics are noted in the following sections.


4.1. Miscellaneous obsolete tokens
4.1. その他の廃止されたトークン

These syntactic elements are used elsewhere in the obsolete syntax or in the main syntax. The obs-char and obs-qp elements each add ASCII value 0. Bare CR and bare LF are added to obs-text and obs-utext. The period character is added to obs-phrase. The obs-phrase-list provides for "empty" elements in a comma-separated list of phrases.

これらの構文要素は廃止された構文で、またはメイン構文の他の場所で使用されています。 OBS-チャーとOBS-QP要素それぞれはASCII値を追加0ベアCRと裸のLFは、OBSテキストとOBS-のutextに添加されます。ピリオド文字は、OBS-フレーズに追加されます。 OBS-フレーズリストは、フレーズのコンマ区切りのリストで「空」の要素のために用意されています。

Note: The "period" (or "full stop") character (".") in obs-phrase is not a form that was allowed in earlier versions of this or any other standard. Period (nor any other character from specials) was not allowed in phrase because it introduced a parsing difficulty distinguishing between phrases and portions of an addr-spec (see section 4.4). It appears here because the period character is currently used in many messages in the display-name portion of addresses, especially for initials in names, and therefore must be interpreted properly. In the future, period may appear in the regular syntax of phrase.


obs-qp = "\" (%d0-127)

OBS-QP = "\"(%のd0-127)

obs-text = *LF *CR *(obs-char *LF *CR) obs-char = %d0-9 / %d11 / ; %d0-127 except CR and %d12 / %d14-127 ; LF

OBSテキスト= * LF * CR *(OBS-のchar * LF * CR)OBS-チャー=%d0-9 /%D11 /。 %d0-127 CRおよび%D12 /%d14-127除きます。 LF

obs-utext = obs-text

OBS =用OBS-テキストのutext

obs-phrase = word *(word / "." / CFWS)

OBS-フレーズ=ワード*(ワード/ "" / CFWS)

obs-phrase-list = phrase / 1*([phrase] [CFWS] "," [CFWS]) [phrase]

OBSフレーズリスト=フレーズ/ 1 *([語句] [CFWS] "" [CFWS])[語句]

Bare CR and bare LF appear in messages with two different meanings. In many cases, bare CR or bare LF are used improperly instead of CRLF to indicate line separators. In other cases, bare CR and bare LF are used simply as ASCII control characters with their traditional ASCII meanings.


4.2. Obsolete folding white space
4.2. 廃止された折り畳み式のホワイトスペース

In the obsolete syntax, any amount of folding white space MAY be inserted where the obs-FWS rule is allowed. This creates the possibility of having two consecutive "folds" in a line, and therefore the possibility that a line which makes up a folded header field could be composed entirely of white space.


obs-FWS = 1*WSP *(CRLF 1*WSP)

FWS-OBS = 1 * WSP(1つのCRLF * WSP)

4.3. Obsolete Date and Time
4.3. 廃止された日付と時刻

The syntax for the obsolete date format allows a 2 digit year in the date field and allows for a list of alphabetic time zone specifications that were used in earlier versions of this standard. It also permits comments and folding white space between many of the tokens.


obs-day-of-week = [CFWS] day-name [CFWS]

OBS-曜日= [CFWS]日名[CFWS]

obs-year = [CFWS] 2*DIGIT [CFWS]


obs-month = CFWS month-name CFWS


obs-day = [CFWS] 1*2DIGIT [CFWS]


obs-hour = [CFWS] 2DIGIT [CFWS]


obs-minute = [CFWS] 2DIGIT [CFWS]


obs-second = [CFWS] 2DIGIT [CFWS]


obs-zone = "UT" / "GMT" / ; Universal Time

OBS-ゾーン= "OUT" / "GMT" /;世界時

                                                ; North American UT
                                                ; offsets
                        "EST" / "EDT" /         ; Eastern:  - 5/ - 4
                        "CST" / "CDT" /         ; Central:  - 6/ - 5
                        "MST" / "MDT" /         ; Mountain: - 7/ - 6
                        "PST" / "PDT" /         ; Pacific:  - 8/ - 7

%d65-73 / ; Military zones - "A" %d75-90 / ; through "I" and "K" %d97-105 / ; through "Z", both %d107-122 ; upper and lower case

%d65-73 /。軍事ゾーン - "" %のd75-90 /; / "I" と "K" %のd97-105を通じて、 "Z"、両方%のd107-122介して、大文字と小文字

Where a two or three digit year occurs in a date, the year is to be interpreted as follows: If a two digit year is encountered whose value is between 00 and 49, the year is interpreted by adding 2000, ending up with a value between 2000 and 2049. If a two digit year is encountered with a value between 50 and 99, or any three digit year is encountered, the year is interpreted by adding 1900.

二、三桁の年が日付で発生した場合は、年は次のように解釈されるべきである:2桁の年は、その値が00と49の間で発生した場合、年が間の値で終わる、2000を追加することによって解釈されます2000および2049 2桁の年が50と99の間の値で遭遇する、または任意の3桁の年が発生した場合、年は1900を追加することによって解釈されます。

In the obsolete time zone, "UT" and "GMT" are indications of "Universal Time" and "Greenwich Mean Time" respectively and are both semantically identical to "+0000".


The remaining three character zones are the US time zones. The first letter, "E", "C", "M", or "P" stands for "Eastern", "Central", "Mountain" and "Pacific". The second letter is either "S" for "Standard" time, or "D" for "Daylight" (or summer) time. Their interpretations are as follows:


EDT is semantically equivalent to -0400 EST is semantically equivalent to -0500 CDT is semantically equivalent to -0500 CST is semantically equivalent to -0600 MDT is semantically equivalent to -0600 MST is semantically equivalent to -0700 PDT is semantically equivalent to -0700 PST is semantically equivalent to -0800

EDTは-0500 CDTと意味的に等価であることは-0500 CSTと意味的に等価である-0400 ESTと意味的に等価であること-0600 MDTと意味的に等価である-0600 MSTと意味的に等価である-0700 PDTと意味的に等価である-0700 PSTと意味的に等価です-0800と同じ意味であります

The 1 character military time zones were defined in a non-standard way in [RFC822] and are therefore unpredictable in their meaning. The original definitions of the military zones "A" through "I" are equivalent to "+0100" through "+0900" respectively; "K", "L", and "M" are equivalent to "+1000", "+1100", and "+1200" respectively; "N" through "Y" are equivalent to "-0100" through "-1200" respectively; and "Z" is equivalent to "+0000". However, because of the error in [RFC822], they SHOULD all be considered equivalent to "-0000" unless there is out-of-band information confirming their meaning.

1つの文字軍用タイムゾーンが[RFC822]で非標準的な方法で定義されており、その意味で、したがって予測できませんされました。 ;「I」は、それぞれ「0900」から「0100」に相当するを通じて軍事ゾーン「A」のオリジナルの定義「K」、「L」、および「M」は「+1000」、「1100」と同等であり、それぞれ「1200」。 「Y」から「N」は、それぞれ「-1200」から「-0100」に相当します。および「Z」は「0000」と同等です。その意味を確認したアウトオブバンド情報がある場合を除きしかし、[RFC822]でのエラーのため、それらはすべて同等に「-0000」を考慮すべきです。

Other multi-character (usually between 3 and 5) alphabetic time zones have been used in Internet messages. Any such time zone whose meaning is not known SHOULD be considered equivalent to "-0000" unless there is out-of-band information confirming their meaning.


4.4. Obsolete Addressing
4.4. アドレッシング廃止

There are three primary differences in addressing. First, mailbox addresses were allowed to have a route portion before the addr-spec when enclosed in "<" and ">". The route is simply a comma-separated list of domain names, each preceded by "@", and the list terminated by a colon. Second, CFWS were allowed between the period-separated elements of local-part and domain (i.e., dot-atom was not used). In addition, local-part is allowed to contain quoted-string in addition to just atom. Finally, mailbox-list and address-list were allowed to have "null" members. That is, there could be two or more commas in such a list with nothing in between them.


obs-angle-addr = [CFWS] "<" [obs-route] addr-spec ">" [CFWS]

OBS角-ADDR = [CFWS] "<" [OBSルート] ADDR仕様 ">" [CFWS]

obs-route = [CFWS] obs-domain-list ":" [CFWS]

OBS-ルート= [CFWS] OBS-ドメインリスト ":" [CFWS]

obs-domain-list = "@" domain *(*(CFWS / "," ) [CFWS] "@" domain)

OBS-ドメインリスト= "@" ドメイン*(*(CFWS / "")[CFWS] "@" ドメイン)

obs-local-part = word *("." word)

OBS-ローカル部分=単語*( "" 単語)

obs-domain = atom *("." atom)

OBS-ドメイン=原子*( "" 原子)

obs-mbox-list = 1*([mailbox] [CFWS] "," [CFWS]) [mailbox]

OBS-MBOXリスト= 1 *([ポスト] [CFWS] "" [CFWS])[メールボックス]

obs-addr-list = 1*([address] [CFWS] "," [CFWS]) [address]

OBS-ADDR-リスト= 1 *([アドレス] [CFWS] "" [CFWS])[住所]

When interpreting addresses, the route portion SHOULD be ignored.


4.5. Obsolete header fields
4.5. 廃止されたヘッダフィールド

Syntactically, the primary difference in the obsolete field syntax is that it allows multiple occurrences of any of the fields and they may occur in any order. Also, any amount of white space is allowed before the ":" at the end of the field name.


obs-fields = *(obs-return / obs-received / obs-orig-date / obs-from / obs-sender / obs-reply-to / obs-to / obs-cc / obs-bcc / obs-message-id / obs-in-reply-to / obs-references / obs-subject / obs-comments / obs-keywords / obs-resent-date / obs-resent-from / obs-resent-send / obs-resent-rply / obs-resent-to / obs-resent-cc / obs-resent-bcc / obs-resent-mid / obs-optional)

OBSフィールド= *(OBSリターン/ OBS-受信/ OBS-ORIG-日付/ OBS-から/ OBS-センダ/ OBS-返信する/ OBS-へ/ OBS-CC / OBS-BCC / OBS-message- ID / OBS・イン・返信先/ OBS-参照/ OBS-対象/ OBS-コメント/ OBS-キーワード/ OBS-再送日付/ OBS-再送-から/ OBS-再送-SEND / OBS-再送-rply / OBS-再送対/ OBS-再送-CC / OBS-再送-BCC / OBS-再送-MID / OBS-オプション)

Except for destination address fields (described in section 4.5.3), the interpretation of multiple occurrences of fields is unspecified. Also, the interpretation of trace fields and resent fields which do not occur in blocks prepended to the message is unspecified as well. Unless otherwise noted in the following sections, interpretation of other fields is identical to the interpretation of their non-obsolete counterparts in section 3.


4.5.1. Obsolete origination date field
4.5.1. 廃止された発信日付フィールド

obs-orig-date = "Date" *WSP ":" date-time CRLF

OBS-ORIG-日付= "日" * WSP ":" 日時CRLF

4.5.2. Obsolete originator fields
4.5.2. 廃止された発信元フィールド

obs-from = "From" *WSP ":" mailbox-list CRLF

OBS-から* WSP "から" = ":" メールボックスリストCRLF

obs-sender = "Sender" *WSP ":" mailbox CRLF

OBS送信= "送信者" * WSP ":" メールボックスCRLF

obs-reply-to = "Reply-To" *WSP ":" mailbox-list CRLF

OBS-応答が-する= "返信先" * WSP ":" メールボックスリストCRLF

4.5.3. Obsolete destination address fields
4.5.3. 廃止された宛先アドレスフィールド

obs-to = "To" *WSP ":" address-list CRLF

OBS-へ "を" * WSP = ":" アドレスリストCRLF

obs-cc = "Cc" *WSP ":" address-list CRLF

OBS-CC = "CC" * WSP ":" アドレスリストCRLF

obs-bcc = "Bcc" *WSP ":" (address-list / [CFWS]) CRLF

OBS-BCC = "のBcc" * WSP ":"(アドレスリスト/ [CFWS])CRLF

When multiple occurrences of destination address fields occur in a message, they SHOULD be treated as if the address-list in the first occurrence of the field is combined with the address lists of the subsequent occurrences by adding a comma and concatenating.


4.5.4. Obsolete identification fields
4.5.4. 廃止された識別フィールド

The obsolete "In-Reply-To:" and "References:" fields differ from the current syntax in that they allow phrase (words or quoted strings) to appear. The obsolete forms of the left and right sides of msg-id allow interspersed CFWS, making them syntactically identical to local-part and domain respectively.

「イン返信先:」時代遅れと「参考文献:」フィールドは、その中で現在の構文とは異なり、彼らは、フレーズ(単語や引用符で囲まれた文字列)が表示されますすることができます。 MSG-IDの左右の廃止された形態は、それぞれのローカル部分とドメインには、構文的に同一の製造、散在CFWSを可能にします。

obs-message-id = "Message-ID" *WSP ":" msg-id CRLF

OBSメッセージ-ID = "メッセージID" * WSP ":" MSG-ID CRLF

obs-in-reply-to = "In-Reply-To" *WSP ":" *(phrase / msg-id) CRLF

OBS・イン・返信先 "では、返信先" * WSP = ":" *(フレーズ/ MSG-ID)CRLF

obs-references = "References" *WSP ":" *(phrase / msg-id) CRLF

OBS-参照= "参考資料" * WSP ":" *(フレーズ/ MSG-ID)CRLF

obs-id-left = local-part


obs-id-right = domain


For purposes of interpretation, the phrases in the "In-Reply-To:" and "References:" fields are ignored.


Semantically, none of the optional CFWS surrounding the local-part and the domain are part of the obs-id-left and obs-id-right respectively.


4.5.5. Obsolete informational fields
4.5.5. 廃止された情報フィールド

obs-subject = "Subject" *WSP ":" unstructured CRLF

OBS-件名= "件名" * WSP ":" 非構造化CRLF

obs-comments = "Comments" *WSP ":" unstructured CRLF

OBS-コメント= "コメント" * WSP ":" 非構造化CRLF

obs-keywords = "Keywords" *WSP ":" obs-phrase-list CRLF

OBS-キーワード= "キーワード" * WSP ":" OBS-フレーズリストCRLF

4.5.6. Obsolete resent fields
4.5.6. 廃止された再送フィールド

The obsolete syntax adds a "Resent-Reply-To:" field, which consists of the field name, the optional comments and folding white space, the colon, and a comma separated list of addresses.


obs-resent-from = "Resent-From" *WSP ":" mailbox-list CRLF

OBS-再送-から= * "のResent-から" WSP ":" メールボックスリストCRLF

obs-resent-send = "Resent-Sender" *WSP ":" mailbox CRLF obs-resent-date = "Resent-Date" *WSP ":" date-time CRLF

OBS-再送-送信= "憤慨し、送信者" * WSP ":" メールボックスCRLFのOBS-再送-日付= "憤慨し-日" * WSP ":" 日時CRLF

obs-resent-to = "Resent-To" *WSP ":" address-list CRLF

":" アドレス一覧CRLF = "憤慨し-へ" * WSP OBS-再送-へ

obs-resent-cc = "Resent-Cc" *WSP ":" address-list CRLF

OBS-再送-CC = "憤慨し-CC" * WSP ":" アドレスリストCRLF

obs-resent-bcc = "Resent-Bcc" *WSP ":" (address-list / [CFWS]) CRLF

OBS-再送-BCC = "憤慨し-BCC" * WSP ":"(アドレスリスト/ [CFWS])CRLF

obs-resent-mid = "Resent-Message-ID" *WSP ":" msg-id CRLF

OBS-再送-MID = "憤慨し、メッセージID" * WSP ":" MSG-ID CRLF

obs-resent-rply = "Resent-Reply-To" *WSP ":" address-list CRLF

OBS-再送-rply = "憤慨し、返信先" * WSP ":" アドレスリストCRLF

As with other resent fields, the "Resent-Reply-To:" field is to be treated as trace information only.


4.5.7. Obsolete trace fields
4.5.7. 廃止されたトレースフィールド

The obs-return and obs-received are again given here as template definitions, just as return and received are in section 3. Their full syntax is given in [RFC2821].


obs-return = "Return-Path" *WSP ":" path CRLF

OBS-リターン= "リターンパスを" * WSPを ":" パスCRLF

obs-received = "Received" *WSP ":" name-val-list CRLF

":" 名-valをリストCRLF = "受信" * WSP OBS-受信

obs-path = obs-angle-addr


4.5.8. Obsolete optional fields
4.5.8. 廃止されたオプションのフィールド

obs-optional = field-name *WSP ":" unstructured CRLF

OBS-オプション=フィールド名* WSP ":" 非構造化CRLF

5. Security Considerations

Care needs to be taken when displaying messages on a terminal or terminal emulator. Powerful terminals may act on escape sequences and other combinations of ASCII control characters with a variety of consequences. They can remap the keyboard or permit other modifications to the terminal which could lead to denial of service or even damaged data. They can trigger (sometimes programmable) answerback messages which can allow a message to cause commands to be issued on the recipient's behalf. They can also effect the operation of terminal attached devices such as printers. Message viewers may wish to strip potentially dangerous terminal escape sequences from the message prior to display. However, other escape sequences appear in messages for useful purposes (cf. [RFC2045, RFC2046, RFC2047, RFC2048, RFC2049, ISO2022]) and therefore should not be stripped indiscriminately.


Transmission of non-text objects in messages raises additional security issues. These issues are discussed in [RFC2045, RFC2046, RFC2047, RFC2048, RFC2049].


Many implementations use the "Bcc:" (blind carbon copy) field described in section 3.6.3 to facilitate sending messages to recipients without revealing the addresses of one or more of the addressees to the other recipients. Mishandling this use of "Bcc:" has implications for confidential information that might be revealed, which could eventually lead to security problems through knowledge of even the existence of a particular mail address. For example, if using the first method described in section 3.6.3, where the "Bcc:" line is removed from the message, blind recipients have no explicit indication that they have been sent a blind copy, except insofar as their address does not appear in the message header. Because of this, one of the blind addressees could potentially send a reply to all of the shown recipients and accidentally reveal that the message went to the blind recipient. When the second method from section 3.6.3 is used, the blind recipient's address appears in the "Bcc:" field of a separate copy of the message. If the "Bcc:" field sent contains all of the blind addressees, all of the "Bcc:" recipients will be seen by each "Bcc:" recipient. Even if a separate message is sent to each "Bcc:" recipient with only the individual's address, implementations still need to be careful to process replies to the message as per section 3.6.3 so as not to accidentally reveal the blind recipient to other recipients.

多くの実装で使用「のBcc:」を(ブラインドカーボンコピー)フィールドは、他の受信者に受取人のうちの1つまたは複数のアドレスを明らかにすることなく、受信者にメッセージを送信する容易にするために、セクション3.6.3で説明しました。この使用誤操作「のBcc:」を最終的に特定のメールアドレスの存在すらの知識によってセキュリティ上の問題につながる可能性が明らかにされるかもしれない機密情報に影響を持っています。 「Bccの:」ここで例えば、セクション3.6.3で説明した第1の方法を使用している場合、行はメッセージから削除され、盲目の受取人は、彼らが自分のアドレスがない限り除き、ブラインドコピーを送信されたことを明示的な兆候を持っていませんメッセージヘッダに現れます。このため、ブラインドアドレスの一つは、潜在的に示したすべての受信者に返信すると、誤ったメッセージがブラインド受信者に行ったことを明らかにできました。メッセージの別のコピーの分野:セクション3.6.3からの第二の方法を使用する場合は、ブラインド受信者のアドレスは、「Bccの」に表示されます。 「BCCが:」場合「のBcc:」送られたフィールドは、ブラインドアドレスのすべてのすべてが含まれている受信者は、それぞれで見られます「のBcc:」受信者を。別のメッセージがそれぞれに送信されている場合でも、「Bccの:」唯一の個人のアドレスを持つ受信者が、実装はまだように、誤って他の受信者にブラインド受信者を明らかにしていないセクション3.6.3あたりのようなメッセージへの返信を処理するために注意する必要があります。

6. Bibliography

[ASCII] American National Standards Institute (ANSI), Coded Character Set - 7-Bit American National Standard Code for Information Interchange, ANSI X3.4, 1986.

[ASCII]米国規格協会(ANSI)、コード化文字セット - 情報交換、ANSI X3.4、1986年のための7ビットの米国標準コード。

[ISO2022] International Organization for Standardization (ISO), Information processing - ISO 7-bit and 8-bit coded character sets - Code extension techniques, Third edition - 1986-05-01, ISO 2022, 1986.

標準化機構(ISO)のために[ISO2022]国際機関、情報処理 - ISO 7ビットと8ビットの符号化文字集合 - コード拡張技術、第3版 - 1986年5月1日、ISO 2022、1986。

[RFC822] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", RFC 822, August 1982.

[RFC822]クロッカー、D.、RFC 822 "標準ARPAインターネットテキストメッセージのフォーマットについて"、1982年8月。

[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996.

[RFC2045]解放され、N.とN. Borenstein、 "マルチパーパスインターネットメールエクステンション(MIME)第一部:インターネットメッセージ本体のフォーマット"、RFC 2045、1996年11月。

[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996.

[RFC2046]解放され、N.とN. Borenstein、 "マルチパーパスインターネットメールエクステンション(MIME)パート2:メディアタイプ"、RFC 2046、1996年11月。

[RFC2047] Moore, K., "Multipurpose Internet Mail Extensions (MIME) Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, November 1996.

[RFC2047]ムーア、K.、 "多目的インターネットメール拡張(MIME)パート3:非ASCIIテキストのためのメッセージヘッダの拡張"、RFC 2047、1996年11月。

[RFC2048] Freed, N., Klensin, J. and J. Postel, "Multipurpose Internet Mail Extensions (MIME) Part Four: Format of Internet Message Bodies", RFC 2048, November 1996.

[RFC2048]解放され、N.、Klensin、J.とJ.ポステル、 "多目的インターネットメール拡張(MIME)第四部:インターネットメッセージ本体のフォーマット"、RFC 2048、1996年11月。

[RFC2049] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples", RFC 2049, November 1996.

[RFC2049]フリード、N.とN. Borenstein、 "マルチパーパスインターネットメールエクステンション(MIME)パート5:適合基準と例"、RFC 2049、1996年11月。

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2119]ブラドナーの、S.、 "要件レベルを示すためにRFCsにおける使用のためのキーワード"、BCP 14、RFC 2119、1997年3月。

[RFC2234] Crocker, D., Editor, and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997.

"構文仕様のための増大しているBNF:ABNF" [RFC2234]クロッカー、D.、エディタ、およびP. Overell、RFC 2234、1997年11月。

[RFC2821] Klensin, J., Editor, "Simple Mail Transfer Protocol", RFC 2821, March 2001.

[RFC2821] Klensin、J.、エディタ、 "簡易メール転送プロトコル"、RFC 2821、2001年3月。

[STD3] Braden, R., "Host Requirements", STD 3, RFC 1122 and RFC 1123, October 1989.

[STD3]ブレーデン、R.、 "ホストの要件"、STD 3、RFC 1122およびRFC 1123、1989年10月。

[STD12] Mills, D., "Network Time Protocol", STD 12, RFC 1119, September 1989.

[STD12]ミルズ、D.、 "ネットワークタイムプロトコル"、STD 12、RFC 1119、1989年9月。

[STD13] Mockapetris, P., "Domain Name System", STD 13, RFC 1034 and RFC 1035, November 1987.

[STD13] Mockapetris、P.、 "ドメインネームシステム"、STD 13、RFC 1034及びRFC 1035、1987年11月。

[STD14] Partridge, C., "Mail Routing and the Domain System", STD 14, RFC 974, January 1986.

[STD14]ウズラ、C.、 "メールルーティングとドメインシステム"、STD 14、RFC 974、1986年1月。

7. Editor's Address

Peter W. Resnick QUALCOMM Incorporated 5775 Morehouse Drive San Diego, CA 92121-1714 USA

ピーター・W.レズニックQUALCOMM Incorporatedの5775モアハウスドライブサンディエゴ、CA 92121から1714 USA

Phone: +1 858 651 4478 Fax: +1 858 651 1102 EMail:

電話:+1 858 651 4478ファックス:+1 858 651 1102 Eメール

8. Acknowledgements

Many people contributed to this document. They included folks who participated in the Detailed Revision and Update of Messaging Standards (DRUMS) Working Group of the Internet Engineering Task Force (IETF), the chair of DRUMS, the Area Directors of the IETF, and people who simply sent their comments in via e-mail. The editor is deeply indebted to them all and thanks them sincerely. The below list includes everyone who sent e-mail concerning this document. Hopefully, everyone who contributed is named here:


Matti Aarnio Barry Finkel Larry Masinter Tanaka Akira Erik Forsberg Denis McKeon Russ Allbery Chuck Foster William P McQuillan Eric Allman Paul Fox Alexey Melnikov Harald Tveit Alvestrand Klaus M. Frank Perry E. Metzger Ran Atkinson Ned Freed Steven Miller Jos Backus Jochen Friedrich Keith Moore Bruce Balden Randall C. Gellens John Gardiner Myers Dave Barr Sukvinder Singh Gill Chris Newman Alan Barrett Tim Goodwin John W. Noerenberg John Beck Philip Guenther Eric Norman J. Robert von Behren Tony Hansen Mike O'Dell Jos den Bekker John Hawkinson Larry Osterman D. J. Bernstein Philip Hazel Paul Overell James Berriman Kai Henningsen Jacob Palme Norbert Bollow Robert Herriot Michael A. Patton Raj Bose Paul Hethmon Uzi Paz Antony Bowesman Jim Hill Michael A. Quinlan Scott Bradner Paul E. Hoffman Eric S. Raymond Randy Bush Steve Hole Sam Roberts Tom Byrer Kari Hurtta Hugh Sasse Bruce Campbell Marco S. Hyman Bart Schaefer Larry Campbell Ofer Inbar Tom Scola W. J. Carpenter Olle Jarnefors Wolfgang Segmuller Michael Chapman Kevin Johnson Nick Shelness Richard Clayton Sudish Joseph John Stanley Maurizio Codogno Maynard Kang Einar Stefferud Jim Conklin Prabhat Keni Jeff Stephenson R. Kelley Cook John C. Klensin Bernard Stern Steve Coya Graham Klyne Peter Sylvester Mark Crispin Brad Knowles Mark Symons Dave Crocker Shuhei Kobayashi Eric Thomas Matt Curtin Peter Koch Lee Thompson Michael D'Errico Dan Kohn Karel De Vriendt Cyrus Daboo Christian Kuhtz Matthew Wall Jutta Degener Anand Kumria Rolf Weber Mark Delany Steen Larsen Brent B. Welch

マッティ・アールニオバリー・フィンケルラリーMasiのケア田中明エリック・フォースバーグデニスマッキオンラスAllberyチャック・フォスターウィリアム・P McQuillan氏の説明によるエリック・オールマン、ポール・フォックスアレクセイ・メルニコフハラルド・トバイット・アルベストランドクラウスM.フランク・ペリーE. Metzgerのはアトキンソンネッドフリードスティーブン・ミラーヨスバッカスヨッヘン・フリードリヒ・キース・ムーアブルースBalden蘭ランドールC. Gellensジョン・ガーディナーマイヤーズデイブ・バーSukvinderシンギルクリス・ニューマンアラン・バレットティム・グッドウィン、ジョンW. Noerenbergジョン・フィリップ・ギュンター・ベック、エリック・ノーマンベッカージョン・ホーキンソンラリー・オスターマンDJ Bernsteinのフィリップ・ハシバミとしてJ.ロバート・フォン・Behrenトニー・ハンセンマイク・オデルヨスポールOverellジェームズBerriman甲斐ヘニングセンヤコブパルメノルベルトBollowロバート・ヘリオットマイケルA.パットンラジボーズポールHethmonウジパズアントニーBowesmanジム・ヒルマイケルA.クインランスコット・ブラッドナーポール・E.ホフマンエリック・レイモンドランディブッシュスティーブ穴サム・ロバーツ、トムByrerカリHurttaヒュー・ザッセブルース・キャンベルマルコS.ハイマンバート・シェーファーラリー・キャンベルオフェルインバートム・スコラWJ大工オルレJarnefors Wolfg HS Segmullerマイケル・チャップマンケビン・ジョンソンニックShelnessリチャード・クレイトンSudishジョセフ・ジョン・スタンレーマウリツィオコドーニョメイナード・カンはEinar Stefferudジム・コンクリンPrabhat Keniジェフ・スティーブンソンR.ケリークックジョンC. Klensinバーナード・スター、スティーブ・グラハムCoya Klyneピーターシルベスターマーク・クリスピンブラッド・ノウルズマーク・シモンズデイブ・クロッカー詩織小林エリック・トーマスマット・カーティンピーター・コッホ・リー・トンプソンマイケルD'Erricoのダン・コーンカレル・デ・VriendtサイラスDabooクリスチャンKuhtzマシュー・ウォールユッタ・デッジナーアナンドKumriaさんロルフ・ウェバーマーク・ディレイニースティーン・ラーセンブレントB.ウェルチ

Steve Dorner Eliot Lear Dan Wing Harold A. Driscoll Barry Leiba Jack De Winter Michael Elkins Jay Levitt Gregory J. Woodhouse Robert Elz Lars-Johan Liman Greg A. Woods Johnny Eriksson Charles Lindsey Kazu Yamamoto Erik E. Fair Pete Loshin Alain Zahm Roger Fajman Simon Lyall Jamie Zawinski Patrik Faltstrom Bill Manning Timothy S. Zurcher Claus Andre Farber John Martin

スティーブ・ドルナーエリオット・リアウィングダン・ハロルドA. Driscollのバリー・レイバジャック・デ・冬のマイケル・エルキンズジェイ・レヴィットグレゴリー・J・ウッドハウスロバート・エルツラース・ヨハンLimanグレッグA.ウッズジョニー・エリクソン・チャールズリンジーカズ山本エリックE.フェアピートLoshinアランZahmロジャーFajmanサイモンライアルジェイミー・ザウィンスキーパトリックFaltstromビル・マニングティモシーS. ZURCHERクラウスアンドレ・ファーバージョン・マーティン

Appendix A. Example messages


This section presents a selection of messages. These are intended to assist in the implementation of this standard, but should not be taken as normative; that is to say, although the examples in this section were carefully reviewed, if there happens to be a conflict between these examples and the syntax described in sections 3 and 4 of this document, the syntax in those sections is to be taken as correct.


   Messages are delimited in this section between lines of "----".  The
   "----" lines are not part of the message itself.

A.1. Addressing examples


The following are examples of messages that might be sent between two individuals.


A.1.1. A message from one person to another with simple addressing


This could be called a canonical message. It has a single author, John Doe, a single recipient, Mary Smith, a subject, the date, a message identifier, and a textual message in the body.


From: John Doe <jdoe@machine.example>
To: Mary Smith <>
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
Message-ID: <1234@local.machine.example>
This is a message just to say hello.
So, "Hello".

If John's secretary Michael actually sent the message, though John was the author and replies to this message should go back to him, the sender field would be used:


From: John Doe <jdoe@machine.example>
Sender: Michael Jones <mjones@machine.example>
To: Mary Smith <>
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
Message-ID: <1234@local.machine.example>
This is a message just to say hello.
So, "Hello".

A.1.2. Different types of mailboxes


This message includes multiple addresses in the destination fields and also uses several different forms of addresses.


From: "Joe Q. Public" <>
To: Mary Smith <mary@x.test>,, Who? <one@y.test>
Cc: <boss@nil.test>, "Giant; \"Big\" Box" <>
Date: Tue, 1 Jul 2003 10:52:37 +0200
Message-ID: <>
Hi everyone.

Note that the display names for Joe Q. Public and Giant; "Big" Box needed to be enclosed in double-quotes because the former contains the period and the latter contains both semicolon and double-quote characters (the double-quote characters appearing as quoted-pair construct). Conversely, the display name for Who? could appear without them because the question mark is legal in an atom. Notice also that and boss@nil.test have no display names associated with them at all, and uses the simpler address form without the angle brackets.


A.1.3. Group addresses


From: Pete <pete@silly.example>
To: A Group:Chris Jones <c@a.test>,joe@where.test,John <jdoe@one.test>;
Cc: Undisclosed recipients:;
Date: Thu, 13 Feb 1969 23:32:54 -0330
Message-ID: <testabcd.1234@silly.example>

In this message, the "To:" field has a single group recipient named A Group which contains 3 addresses, and a "Cc:" field with an empty group recipient named Undisclosed recipients.


A.2. Reply messages


The following is a series of three messages that make up a conversation thread between John and Mary. John firsts sends a message to Mary, Mary then replies to John's message, and then John replies to Mary's reply message.


Note especially the "Message-ID:", "References:", and "In-Reply-To:" fields in each message.


From: John Doe <jdoe@machine.example>
To: Mary Smith <>
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
Message-ID: <1234@local.machine.example>
This is a message just to say hello.
So, "Hello".

When sending replies, the Subject field is often retained, though prepended with "Re: " as described in section 3.6.5.


From: Mary Smith <>
To: John Doe <jdoe@machine.example>
Reply-To: "Mary Smith: Personal Account" <smith@home.example>
Subject: Re: Saying Hello
Date: Fri, 21 Nov 1997 10:01:10 -0600
Message-ID: <>
In-Reply-To: <1234@local.machine.example>
References: <1234@local.machine.example>
This is a reply to your hello.

Note the "Reply-To:" field in the above message. When John replies to Mary's message above, the reply should go to the address in the "Reply-To:" field instead of the address in the "From:" field.


To: "Mary Smith: Personal Account" <smith@home.example>
From: John Doe <jdoe@machine.example>
Subject: Re: Saying Hello
Date: Fri, 21 Nov 1997 11:00:00 -0600
Message-ID: <abcd.1234@local.machine.tld>
In-Reply-To: <>
References: <1234@local.machine.example> <>
This is a reply to your reply.

A.3. Resent messages


Start with the message that has been used as an example several times:


From: John Doe <jdoe@machine.example>
To: Mary Smith <>
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
Message-ID: <1234@local.machine.example>
This is a message just to say hello.
So, "Hello".

Say that Mary, upon receiving this message, wishes to send a copy of the message to Jane such that (a) the message would appear to have come straight from John; (b) if Jane replies to the message, the reply should go back to John; and (c) all of the original information, like the date the message was originally sent to Mary, the message identifier, and the original addressee, is preserved. In this case, resent fields are prepended to the message:


Resent-From: Mary Smith <>
Resent-To: Jane Brown <j-brown@other.example>
Resent-Date: Mon, 24 Nov 1997 14:22:01 -0800
Resent-Message-ID: <>
From: John Doe <jdoe@machine.example>
To: Mary Smith <>
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
Message-ID: <1234@local.machine.example>
This is a message just to say hello.
So, "Hello".

If Jane, in turn, wished to resend this message to another person, she would prepend her own set of resent header fields to the above and send that.


A.4. Messages with trace fields


As messages are sent through the transport system as described in [RFC2821], trace fields are prepended to the message. The following is an example of what those trace fields might look like. Note that there is some folding white space in the first one since these lines can be long.


Received: from x.y.test
   via TCP
   with ESMTP
   id ABC12345
   for <>;  21 Nov 1997 10:05:43 -0600
Received: from machine.example by x.y.test; 21 Nov 1997 10:01:22 -0600
From: John Doe <jdoe@machine.example>
To: Mary Smith <>
Subject: Saying Hello
Date: Fri, 21 Nov 1997 09:55:06 -0600
Message-ID: <1234@local.machine.example>
This is a message just to say hello.
So, "Hello".

A.5. White space, comments, and other oddities


White space, including folding white space, and comments can be inserted between many of the tokens of fields. Taking the example from A.1.3, white space and comments can be inserted into all of the fields.

ホワイトホワイトスペースを折るなどのスペース、およびコメントは、フィールドのトークンの多くの間に挿入することができます。 A.1.3の例を取っ​​て、空白やコメントは、すべてのフィールドに挿入することができます。

From: Pete(A wonderful \) chap) <pete(his account)@silly.test(his host)>
To:A Group(Some people)
     :Chris Jones <c@(Chris's host.)public.example>,,
  John <jdoe@one.test> (my dear friend); (the end of the group)
Cc:(Empty list)(start)Undisclosed recipients  :(nobody(that I know))  ;
Date: Thu,
               -0330 (Newfoundland Time)
Message-ID:              <testabcd.1234@silly.test>

The above example is aesthetically displeasing, but perfectly legal. Note particularly (1) the comments in the "From:" field (including one that has a ")" character appearing as part of a quoted-pair); (2) the white space absent after the ":" in the "To:" field as well as the comment and folding white space after the group name, the special character (".") in the comment in Chris Jones's address, and the folding white space before and after ","; (3) the multiple and nested comments in the "Cc:" field as well as the comment immediately following the ":" after "Cc"; (4) the folding white space (but no comments except at the end) and the missing seconds in the time of the date field; and (5) the white space before (but not within) the identifier in the "Message-ID:" field.

上記の例では、審美的に不快な、しかし完全に合法です。注特に(1)の「From:」のコメント引用対の一部)として現れる文字フィールド(持つ含む一つ「)を」。 (2)の後に不在の空白「:」中「に:」フィールドだけでなく、コメントやクリス・ジョーンズのアドレスでのコメントで、グループ名の後に空白を折りたたみ、特殊文字(「」)、との「」の前後に空白を折ります。 (3)「CC:」で複数のとネストされたコメントは、「:」の後に「CC」、フィールドだけでなく、コメントはすぐに次のよう(4)折りたたみホワイトスペース(しかし最後を除いコメントなし)と日付フィールドの時間で欠落秒。および(5)で(ただし以内)識別子の前にホワイトスペース「のMessage-ID:」フィールド。

A.6. Obsoleted forms


The following are examples of obsolete (that is, the "MUST NOT generate") syntactic elements described in section 4 of this document.


A.6.1. Obsolete addressing


Note in the below example the lack of quotes around Joe Q. Public, the route that appears in the address for Mary Smith, the two commas that appear in the "To:" field, and the spaces that appear around the "." in the jdoe address.


From: Joe Q. Public <>
To: Mary Smith <>, , jdoe@test   . example
Date: Tue, 1 Jul 2003 10:52:37 +0200
Message-ID: <>
Hi everyone.

A.6.2. Obsolete dates


The following message uses an obsolete date format, including a non-numeric time zone and a two digit year. Note that although the day-of-week is missing, that is not specific to the obsolete syntax; it is optional in the current syntax as well.


From: John Doe <jdoe@machine.example>
To: Mary Smith <>
Subject: Saying Hello
Date: 21 Nov 97 09:55:06 GMT
Message-ID: <1234@local.machine.example>
This is a message just to say hello.
So, "Hello".

A.6.3. Obsolete white space and comments


White space and comments can appear between many more elements than in the current syntax. Also, folding lines that are made up entirely of white space are legal.


From  : John Doe <jdoe@machine(comment).  example>
To    : Mary Smith
Subject     : Saying Hello
Date  : Fri, 21 Nov 1997 09(comment):   55  :  06 -0600
Message-ID  : <1234   @   local(blah)  .machine .example>
This is a message just to say hello.
So, "Hello".

Note especially the second line of the "To:" field. It starts with two space characters. (Note that "__" represent blank spaces.) Therefore, it is considered part of the folding as described in section 4.2. Also, the comments and white space throughout addresses, dates, and message identifiers are all part of the obsolete syntax.


Appendix B. Differences from earlier standards


This appendix contains a list of changes that have been made in the Internet Message Format from earlier standards, specifically [RFC822] and [STD3]. Items marked with an asterisk (*) below are items which appear in section 4 of this document and therefore can no longer be generated.


1. Period allowed in obsolete form of phrase. 2. ABNF moved out of document to [RFC2234]. 3. Four or more digits allowed for year. 4. Header field ordering (and lack thereof) made explicit. 5. Encrypted header field removed. 6. Received syntax loosened to allow any token/value pair. 7. Specifically allow and give meaning to "-0000" time zone. 8. Folding white space is not allowed between every token. 9. Requirement for destinations removed. 10. Forwarding and resending redefined. 11. Extension header fields no longer specifically called out. 12. ASCII 0 (null) removed.* 13. Folding continuation lines cannot contain only white space.* 14. Free insertion of comments not allowed in date.* 15. Non-numeric time zones not allowed.* 16. Two digit years not allowed.* 17. Three digit years interpreted, but not allowed for generation. 18. Routes in addresses not allowed.* 19. CFWS within local-parts and domains not allowed.* 20. Empty members of address lists not allowed.*

句の廃止された形で許さ1.期間。 2. ABNFは、[RFC2234]に文書の外に移動しました。年に許可される3つ以上の数字。 4.ヘッダーフィールドの順序(およびその欠如)が明示的に。前記暗号化ヘッダフィールドを除去します。 6.受信した構文は、どのトークン/値のペアを許可するように緩め。 7.具体的に許可すると「-0000」の時間帯に意味を与えます。 8.折りたたみ空白はすべてのトークンの間で許可されていません。目的地9.要件を削除します。 10.転送と再送を再定義しました。 11.拡張ヘッダフィールドは、もはや具体呼び出しません。 12. ASCII 0(ヌル)を除去する。* 13.折りたたみ継続行のみ空白を含めることはできません。コメントの* 14.無料挿入は日付で許可されていません。* 15非数値のタイムゾーンが許可されていません。* 16 2桁の年許可されていません。* 17.三桁の年の解釈が、世代のために許可されていません。アドレス18.ルートは許可されていません。*ローカル部分とドメイン内の19 CFWSが許可されていません。アドレスリストの* 20.空のメンバーが許可されていません。*

21. Folding white space between field name and colon not allowed.* 22. Comments between field name and colon not allowed. 23. Tightened syntax of in-reply-to and references.* 24. CFWS within msg-id not allowed.* 25. Tightened semantics of resent fields as informational only. 26. Resent-Reply-To not allowed.* 27. No multiple occurrences of fields (except resent and received).* 28. Free CR and LF not allowed.* 29. Routes in return path not allowed.* 30. Line length limits specified. 31. Bcc more clearly specified.

21.許可されていないフィールド名とコロンの間の空白を折りたたみ。*フィールド名とコロンの間で22のコメントが許可されていません。 23.中・返信先および参照の構文を強化した。*許可されていませんMSG-ID内の24 CFWS。情報提供のみとして再送フィールドの* 25.厳しくなっセマンティクスが。 26のResent-返信することはできません。* 27フィールドのない複数の発生(再送を除くと受信)。許可されていない* 28無料CRとLF。許可されていない復路の* 29.ルート。* 30行の長さ制限が指定されています。 31. Bccのは、より明確に指定されました。

Appendix C. Notices


Intellectual Property


The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat.


Full Copyright Statement


Copyright (C) The Internet Society (2001). All Rights Reserved.


This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.


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