draft-ietf-eai-rfc5337bis-dsn-06.txt   rfc6533.txt 
Network Working Group T. Hansen, Ed. Internet Engineering Task Force (IETF) T. Hansen, Ed.
Internet-Draft AT&T Laboratories Request for Comments: 6533 AT&T Laboratories
Obsoletes: 5337 (if approved) C. Newman Obsoletes: 5337 C. Newman
Updates: 3461, 3462, 3464, 3798 Oracle Updates: 3461, 3464, 3798, 6522 Oracle
(if approved) A. Melnikov Category: Standards Track A. Melnikov
Intended status: Standards Track Isode Ltd ISSN: 2070-1721 Isode Ltd
Expires: May 17, 2012 November 14, 2011 February 2012
Internationalized Delivery Status and Disposition Notifications Internationalized Delivery Status and Disposition Notifications
draft-ietf-eai-rfc5337bis-dsn-06
Abstract Abstract
Delivery status notifications (DSNs) are critical to the correct Delivery status notifications (DSNs) are critical to the correct
operation of an email system. However, the existing Draft Standards operation of an email system. However, the existing Draft Standards
(RFC 3461, RFC 3462, RFC 3464) are presently limited to US-ASCII text (RFC 3461, RFC 3464, RFC 6522) are presently limited to ASCII text in
in the machine-readable portions of the protocol. This specification the machine-readable portions of the protocol. This specification
adds a new address type for international email addresses so an adds a new address type for international email addresses so an
original recipient address with non-US-ASCII characters can be original recipient address with non-ASCII characters can be correctly
correctly preserved even after downgrading. This also provides preserved even after downgrading. This also provides updated content
updated content return media types for delivery status notifications return media types for delivery status notifications and message
and message disposition notifications to support use of the new disposition notifications to support use of the new address type.
address type.
This document extends RFC 3461, RFC 3462, RFC 3464, and RFC 3798. It This document extends RFC 3461, RFC 3464, RFC 3798, and RFC 6522.
replaces the experimental RFC 5337.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
This Internet-Draft will expire on May 17, 2012. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6533.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 3 2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. UTF-8 Address Type . . . . . . . . . . . . . . . . . . . . . . 3 3. UTF-8 Address Type . . . . . . . . . . . . . . . . . . . . . . 3
4. UTF-8 Delivery Status Notifications . . . . . . . . . . . . . 6 4. UTF-8 Delivery Status Notifications . . . . . . . . . . . . . 6
4.1. The message/global-delivery-status Media Type . . . . . . 6 4.1. The message/global-delivery-status Media Type . . . . . . 6
4.2. The message/global Media Type . . . . . . . . . . . . . . 9 4.2. The message/global Media Type . . . . . . . . . . . . . . 8
4.3. The message/global-headers Media Type . . . . . . . . . . 9 4.3. The message/global-headers Media Type . . . . . . . . . . 8
4.4. Using These Media Types with multipart/report . . . . . . 9 4.4. Using These Media Types with multipart/report . . . . . . 8
4.5. Additional Requirements on SMTP Servers . . . . . . . . . 9 4.5. Additional Requirements on SMTP Servers . . . . . . . . . 9
5. UTF-8 Message Disposition Notifications . . . . . . . . . . . 10 5. UTF-8 Message Disposition Notifications . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
6.1. UTF-8 Mail Address Type Registration . . . . . . . . . . . 11 6.1. UTF-8 Mail Address Type Registration . . . . . . . . . . . 10
6.2. Update to 'smtp' Diagnostic Type Registration . . . . . . 11 6.2. Update to 'smtp' Diagnostic Type Registration . . . . . . 11
6.3. message/global-headers . . . . . . . . . . . . . . . . . . 12 6.3. message/global-headers . . . . . . . . . . . . . . . . . . 11
6.4. message/global-delivery-status . . . . . . . . . . . . . . 13 6.4. message/global-delivery-status . . . . . . . . . . . . . . 12
6.5. message/global-disposition-notification . . . . . . . . . 14 6.5. message/global-disposition-notification . . . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 15 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1. Normative References . . . . . . . . . . . . . . . . . . . 16 8.1. Normative References . . . . . . . . . . . . . . . . . . . 16
8.2. Informative References . . . . . . . . . . . . . . . . . . 17 8.2. Informative References . . . . . . . . . . . . . . . . . . 17
Appendix A. Changes Since RFC 5337 . . . . . . . . . . . . . . . 18 Appendix A. Changes since RFC 5337 . . . . . . . . . . . . . . . 18
Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 18 Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
When an email message is transmitted using the UTF8SMTP When an email message is transmitted using the SMTPUTF8 [RFC6531]
[I-D.ietf-eai-rfc5336bis] extension and Internationalized Email extension and Internationalized Email Headers [RFC6532], it is
Headers [I-D.ietf-eai-rfc5335bis], it is sometimes necessary to sometimes necessary to return that message or generate a Message
return that message or generate a Message Disposition Notification Disposition Notification (MDN) [RFC3798]. As a message sent to
(MDN) [RFC3798]. As a message sent to multiple recipients can multiple recipients can generate a status and disposition
generate a status and disposition notification for each recipient, it notification for each recipient, it is helpful if a client can
is helpful if a client can correlate these notifications based on the correlate these notifications based on the recipient address it
recipient address it provided; thus, preservation of the original provided; thus, preservation of the original recipient is important.
recipient is important. This specification describes how to preserve This specification describes how to preserve the original recipient
the original recipient and updates the MDN and DSN formats to support and updates the MDN and DSN formats to support the new address types.
the new address types.
NOTE: While this specification updates the experimental versions of NOTE: While this specification updates the experimental versions of
this protocol by removing certain constructs (e.g., the "<addr this protocol by removing certain constructs (e.g., the "<addr
<addr>>" address syntax is no longer permitted), the name of the <addr>>" address syntax is no longer permitted), the name of the
Address Type "UTF-8" and the media type names message/global, Address Type "UTF-8" and the media type names message/global,
message/global-delivery-status and message/global-headers have not message/global-delivery-status, and message/global-headers have not
been changed. been changed.
This specification is a revision of and replacement for [RFC5337]. This specification is a revision of and replacement for [RFC5337].
Section 6 of [I-D.ietf-eai-frmwrk-4952bis] describes the change in Section 6 of [RFC6530] describes the change in approach between this
approach between this specification and the previous version. specification and the previous version.
2. Conventions Used in This Document 2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
The formal syntax uses the Augmented Backus-Naur Form (ABNF) The formal syntax uses the Augmented Backus-Naur Form (ABNF)
[RFC5234] notation including the core rules defined in Appendix B of [RFC5234] notation including the core rules defined in Appendix B of
RFC 5234 [RFC5234] and the UTF-8 syntax rules in Section 4 of [RFC5234] and the UTF-8 syntax rules in Section 4 of [RFC3629].
[RFC3629].
3. UTF-8 Address Type 3. UTF-8 Address Type
An Extensible Message Format for Delivery Status Notifications "An Extensible Message Format for Delivery Status Notifications"
[RFC3464] defines the concept of an address type. The address format [RFC3464] defines the concept of an address type. The address format
introduced in Internationalized Email Headers introduced in "Internationalized Email Headers" [RFC6532] is a new
[I-D.ietf-eai-rfc5335bis] is a new address type. The syntax for the address type. The syntax for the new address type in the context of
new address type in the context of status notifications is specified status notifications is specified at the end of this section.
at the end of this section.
An SMTP [RFC5321] server that advertises both the UTF8SMTP extension An SMTP [RFC5321] server that advertises both the SMTPUTF8 extension
[I-D.ietf-eai-rfc5336bis] and the DSN extension [RFC3461] MUST accept [RFC6531] and the DSN extension [RFC3461] MUST accept a UTF-8 address
a UTF-8 address type in the ORCPT parameter including 8-bit UTF-8 type in the ORCPT parameter including 8-bit UTF-8 characters. This
characters. This address type also includes a 7-bit encoding address type also includes a 7-bit encoding suitable for use in a
suitable for use in a message/delivery-status body part or an ORCPT message/delivery-status body part or an ORCPT parameter sent to an
parameter sent to an SMTP server that does not advertise UTF8SMTP. SMTP server that does not advertise SMTPUTF8.
This address type has 3 forms: utf-8-addr-xtext, utf-8-addr-unitext, This address type has 3 forms: utf-8-addr-xtext, utf-8-addr-unitext,
and utf-8-address. Only the first form is 7-bit safe (only uses US- and utf-8-address. Only the first form is 7-bit safe (only uses
ASCII characters). ASCII characters [ASCII]).
The utf-8-address form is only suitable for use in newly defined The utf-8-address form is only suitable for use in newly defined
protocols capable of native representation of 8-bit characters. That protocols capable of native representation of 8-bit characters. That
is, the utf-8-address form MUST NOT be used: is, the utf-8-address form MUST NOT be used:
1. in the ORCPT parameter when the SMTP server doesn't advertise 1. in the ORCPT parameter when the SMTP server doesn't advertise
support for UTF8SMTP (utf-8-addr-xtext MUST be used instead); or support for SMTPUTF8 (utf-8-addr-xtext MUST be used instead); or
2. the SMTP server supports UTF8SMTP, but the address contains US- 2. if the SMTP server supports SMTPUTF8, but the address contains
ASCII characters not permitted in the ORCPT parameter (e.g., the ASCII characters not permitted in the ORCPT parameter (e.g., the
ORCPT parameter forbids unencoded SP and the = character), ORCPT parameter forbids unencoded SP and the '=' character),
(either utf-8-addr-unitext or utf-8-addr-xtext MUST be used (either utf-8-addr-unitext or utf-8-addr-xtext MUST be used
instead); or instead); or
3. in a 7-bit transport environment including a message/ 3. in a 7-bit transport environment including a message/
delivery-status Original-Recipient or Final-Recipient field, delivery-status "Original-Recipient:" or "Final-Recipient:"
(utf-8-addr-xtext MUST be used instead). field, (utf-8-addr-xtext MUST be used instead).
The utf-8-address form MAY be used in the ORCPT parameter when the The utf-8-address form MAY be used in the ORCPT parameter when the
SMTP server also advertises support for UTF8SMTP and the address SMTP server also advertises support for SMTPUTF8 and the address
doesn't contain any US-ASCII characters not permitted in the ORCPT doesn't contain any ASCII characters not permitted in the ORCPT
parameter. It SHOULD be used in a message/global-delivery-status parameter. It SHOULD be used in a message/global-delivery-status
Original-Recipient or Final-Recipient DSN field, or in an Original- "Original-Recipient:" or "Final-Recipient:" DSN field, or in an
Recipient header field [RFC3798] if the message is a UTF8SMTP "Original-Recipient:" header field [RFC3798] if the message is a
message. SMTPUTF8 message.
In addition, the utf-8-addr-unitext form can be used anywhere where In addition, the utf-8-addr-unitext form can be used anywhere where
the utf-8-address form is allowed. the utf-8-address form is allowed.
When used in the ORCPT parameter, the UTF-8 address type requires When used in the ORCPT parameter, the UTF-8 address type requires
that US-ASCII CTLs, SP, \, +, and = be encoded using 'unitext' that ASCII CTLs, SP, '\', '+', and '=' be encoded using 'unitext'
encoding (see below). This is described by the utf-8-addr-xtext and encoding (see below). This is described by the utf-8-addr-xtext and
utf-8-addr-unitext forms in the ABNF below. The 'unitext' encoding utf-8-addr-unitext forms in the ABNF below. The 'unitext' encoding
uses "\x{HEXPOINT}" syntax (EmbeddedUnicodeChar in the ABNF below) uses "\x{HEXPOINT}" syntax (EmbeddedUnicodeChar in the ABNF below)
for encoding any Unicode character outside of US-ASCII range, as well for encoding any Unicode character outside of ASCII range, as well as
as for encoding CTLs, SP, \, +, and =. HEXPOINT is 2 to 6 for encoding CTLs, SP, '\', '+', and '='. HEXPOINT is 2 to 6
hexadecimal digits. This encoding avoids the need to use the xtext hexadecimal digits. This encoding avoids the need to use the xtext
encoding described in [RFC3461], as any US-ASCII characters that encoding described in [RFC3461], as any ASCII characters that need to
needs to be escaped using xtext encoding never appear in any unitext be escaped using xtext encoding never appear in any unitext-encoded
encoded string. When sending data to a UTF8SMTP capable server, string. When sending data to a SMTPUTF8-capable server, native UTF-8
native UTF-8 characters SHOULD be used instead of the characters SHOULD be used instead of the EmbeddedUnicodeChar syntax
EmbeddedUnicodeChar syntax described in details below. When sending described below. When sending data to an SMTP server that does not
data to an SMTP server that does not advertise UTF8SMTP, then the advertise SMTPUTF8, then the EmbeddedUnicodeChar syntax MUST be used
EmbeddedUnicodeChar syntax MUST be used instead of UTF-8. instead of UTF-8.
When the ORCPT parameter is placed in a message/ When the ORCPT parameter is placed in a message/
global-delivery-status Original-Recipient field, the 'utf-8-addr- global-delivery-status "Original-Recipient:" field, the
xtext' form of the UTF-8 address type SHOULD be converted to the utf-8-addr-xtext form of the UTF-8 address type SHOULD be converted
'utf-8-address' form (see the ABNF below) by removing the 'unitext' to the utf-8-address form (see the ABNF below) by removing the
encoding. However, if an address is labeled with the UTF-8 address unitext encoding. However, if an address is labeled with the UTF-8
type but does not conform to utf-8 syntax, then it MUST be copied address type but does not conform to utf-8 syntax, then it MUST be
into the message/global-delivery-status field without alteration. copied into the message/global-delivery-status field without
alteration.
The ability to encode characters with the EmbeddedUnicodeChar The ability to encode characters with the EmbeddedUnicodeChar
encodings should be viewed as a transitional mechanism and avoided encodings should be viewed as a transitional mechanism and avoided
when possible. It is hoped that as systems lacking support for when possible. It is hoped that as systems lacking support for
UTF8SMTP become less common over time, these encodings can eventually SMTPUTF8 become less common over time, these encodings can eventually
be phased out. be phased out.
In the ABNF below, all productions not defined in this document are In the ABNF below, all productions not defined in this document are
defined in Appendix B of [RFC5234], in Section 4 of [RFC3629], or in defined in Appendix B of [RFC5234], in Section 4 of [RFC3629], or in
[RFC3464]. [RFC3464].
utf-8-type-addr = "utf-8;" utf-8-enc-addr utf-8-type-addr = "utf-8;" utf-8-enc-addr
utf-8-address = Mailbox utf-8-address = Mailbox
; Mailbox as defined in [I-D.ietf-eai-rfc5336bis]. ; Mailbox as defined in [RFC6531].
utf-8-enc-addr = utf-8-addr-xtext / utf-8-enc-addr = utf-8-addr-xtext /
utf-8-addr-unitext / utf-8-addr-unitext /
utf-8-address utf-8-address
utf-8-addr-xtext = 1*(QCHAR / EmbeddedUnicodeChar) utf-8-addr-xtext = 1*(QCHAR / EmbeddedUnicodeChar)
; 7bit form of utf-8-addr-unitext. ; 7bit form of utf-8-addr-unitext.
; Safe for use in the ORCPT [RFC3461] ; Safe for use in the ORCPT [RFC3461]
; parameter even when UTF8SMTP SMTP ; parameter even when SMTPUTF8 SMTP
; extension is not advertised. ; extension is not advertised.
utf-8-addr-unitext = 1*(QUCHAR / EmbeddedUnicodeChar) utf-8-addr-unitext = 1*(QUCHAR / EmbeddedUnicodeChar)
; MUST follow utf-8-address ABNF when ; MUST follow utf-8-address ABNF when
; dequoted. ; dequoted.
; Safe for using in the ORCPT [RFC3461] ; Safe for using in the ORCPT [RFC3461]
; parameter when UTF8SMTP SMTP extension ; parameter when SMTPUTF8 SMTP extension
; is also advertised. ; is also advertised.
QCHAR = %x21-2a / %x2c-3c / %x3e-5b / %x5d-7e QCHAR = %x21-2a / %x2c-3c / %x3e-5b / %x5d-7e
; US-ASCII printable characters except ; ASCII printable characters except
; CTLs, SP, '\', '+', '='. ; CTLs, SP, '\', '+', '='.
QUCHAR = QCHAR / UTF8-2 / UTF8-3 / UTF8-4 QUCHAR = QCHAR / UTF8-2 / UTF8-3 / UTF8-4
; US-ASCII printable characters except ; ASCII printable characters except
; CTLs, SP, '\', '+' and '=', plus ; CTLs, SP, '\', '+' and '=', plus
; other Unicode characters encoded in UTF-8 ; other Unicode characters encoded in UTF-8
EmbeddedUnicodeChar = %x5C.78 "{" HEXPOINT "}" EmbeddedUnicodeChar = %x5C.78 "{" HEXPOINT "}"
; starts with "\x" ; starts with "\x"
HEXPOINT = ( ( "0"/"1" ) %x31-39 ) / "10" / "20" / HEXPOINT = ( ( "0"/"1" ) %x31-39 ) / "10" / "20" /
"2B" / "3D" / "7F" / ; all xtext-specials "2B" / "3D" / "7F" / ; all xtext-specials
"5C" / (HEXDIG8 HEXDIG) / ; 2 digit forms "5C" / (HEXDIG8 HEXDIG) / ; 2-digit forms
( NZHEXDIG 2(HEXDIG) ) / ; 3 digit forms ( NZHEXDIG 2(HEXDIG) ) / ; 3-digit forms
( NZDHEXDIG 3(HEXDIG) ) / ; 4 digit forms excluding ( NZDHEXDIG 3(HEXDIG) ) / ; 4-digit forms excluding
( "D" %x30-37 2(HEXDIG) ) / ; ... surrogate ( "D" %x30-37 2(HEXDIG) ) / ; ... surrogate
( NZHEXDIG 4(HEXDIG) ) / ; 5 digit forms ( NZHEXDIG 4(HEXDIG) ) / ; 5-digit forms
( "10" 4*HEXDIG ) ; 6 digit forms ( "10" 4*HEXDIG ) ; 6-digit forms
; represents either "\" or a Unicode code point outside ; represents either "\" or a Unicode code point outside
; the US-ASCII repertoire ; the ASCII repertoire
HEXDIG8 = %x38-39 / "A" / "B" / "C" / "D" / "E" / "F" HEXDIG8 = %x38-39 / "A" / "B" / "C" / "D" / "E" / "F"
; HEXDIG excluding 0-7 ; HEXDIG excluding 0-7
NZHEXDIG = %x31-39 / "A" / "B" / "C" / "D" / "E" / "F" NZHEXDIG = %x31-39 / "A" / "B" / "C" / "D" / "E" / "F"
; HEXDIG excluding "0" ; HEXDIG excluding "0"
NZDHEXDIG = %x31-39 / "A" / "B" / "C" / "E" / "F" NZDHEXDIG = %x31-39 / "A" / "B" / "C" / "E" / "F"
; HEXDIG excluding "0" and "D" ; HEXDIG excluding "0" and "D"
4. UTF-8 Delivery Status Notifications 4. UTF-8 Delivery Status Notifications
A traditional delivery status notification [RFC3464] comes in a A traditional delivery status notification [RFC3464] comes in a
three-part multipart/report [RFC3462] container, where the first part three-part multipart/report [RFC6522] container, where the first part
is human-readable text describing the error, the second part is a is human-readable text describing the error, the second part is a
7-bit-only message/delivery-status, and the optional third part is 7-bit-only message/delivery-status, and the optional third part is
used for content (message/rfc822) or header (text/rfc822-headers) used for content (message/rfc822) or header (text/rfc822-headers)
return. As the present standard DSN format does not permit the return. As the present standard DSN format does not permit the
return of undeliverable UTF8SMTP messages, three new media types are return of undeliverable SMTPUTF8 messages, three new media types have
needed. ([RFC5337] introduced experimental versions of these media been defined. ([RFC5337] introduced experimental versions of these
types.) media types.)
4.1. The message/global-delivery-status Media Type 4.1. The message/global-delivery-status Media Type
The first type, message/global-delivery-status, has the syntax of The first type, message/global-delivery-status, has the syntax of
message/delivery-status with three modifications. First, the charset message/delivery-status with three modifications. First, the charset
for message/global-delivery-status is UTF-8, and thus any field MAY for message/global-delivery-status is UTF-8, and thus any field MAY
contain UTF-8 characters when appropriate (see the ABNF below). In contain UTF-8 characters when appropriate (see the ABNF below). In
particular, the Diagnostic-Code field MAY contain UTF-8 as described particular, the "Diagnostic-Code:" field MAY contain UTF-8 as
in UTF8SMTP [I-D.ietf-eai-rfc5336bis]; the Diagnostic-Code field described in SMTPUTF8 [RFC6531]; the "Diagnostic-Code:" field SHOULD
SHOULD be in i-default language [RFC2277]. Second, systems be in i-default language [RFC2277]. Second, systems generating a
generating a message/global-delivery-status body part SHOULD use the message/global-delivery-status body part SHOULD use the utf-8-address
utf-8-address form of the UTF-8 address type for all addresses form of the UTF-8 address type for all addresses containing
containing characters outside the US-ASCII repertoire. These systems characters outside the ASCII repertoire. These systems SHOULD up-
SHOULD up-convert the utf-8-addr-xtext or the utf-8-addr-unitext form convert the utf-8-addr-xtext or the utf-8-addr-unitext form of a
of a UTF-8 address type in the ORCPT parameter to the utf-8-address UTF-8 address type in the ORCPT parameter to the utf-8-address form
form of a UTF-8 address type in the Original-Recipient field. Third, of a UTF-8 address type in the "Original-Recipient:" field. Third,
an optional field called Localized-Diagnostic is added. Each an optional field called "Localized-Diagnostic:" is added. Each
instance includes a language tag [RFC5646] and contains text in the instance includes a language tag [RFC5646] and contains text in the
specified language. This is equivalent to the text part of the specified language. This is equivalent to the text part of the
Diagnostic-Code field. All instances of Localized-Diagnostic MUST "Diagnostic-Code:" field. All instances of "Localized-Diagnostic:"
use different language tags. The ABNF for message/ MUST use different language tags. The ABNF for message/
global-delivery-status is specified below. global-delivery-status is specified below.
In the ABNF below, all productions not defined in this document are In the ABNF below, all productions not defined in this document are
defined in Appendix B of [RFC5234], in Section 4 of [RFC3629], or in defined in Appendix B of [RFC5234], in Section 4 of [RFC3629], or in
[RFC3464]. Note that <text-fixed> is the same as <text> from [RFC3464]. Note that <text-fixed> is the same as <text> from
[RFC5322], but without <obs-text>. If or when RFC 5322 is updated to [RFC5322], but without <obs-text>. If or when RFC 5322 is updated to
disallow <obs-text>, this should become just <text>. Also, if or disallow <obs-text>, <text-fixed> should become just <text>. Also,
when RFC 5322 is updated to disallow control characters in <text>, if or when RFC 5322 is updated to disallow control characters in
this should become a reference to that update instead. <text>, <text-fixed> should become a reference to that update
instead.
utf-8-delivery-status-content = per-message-fields utf-8-delivery-status-content = per-message-fields
1*( CRLF utf-8-per-recipient-fields ) 1*( CRLF utf-8-per-recipient-fields )
; "per-message-fields" remains unchanged from the definition ; "per-message-fields" remains unchanged from the definition
; in RFC 3464, except for the "extension-field" ; in RFC 3464, except for the "extension-field",
; which is updated below. ; which is updated below.
utf-8-per-recipient-fields = utf-8-per-recipient-fields =
[ original-recipient-field CRLF ] [ original-recipient-field CRLF ]
final-recipient-field CRLF final-recipient-field CRLF
action-field CRLF action-field CRLF
status-field CRLF status-field CRLF
[ remote-mta-field CRLF ] [ remote-mta-field CRLF ]
[ diagnostic-code-field CRLF [ diagnostic-code-field CRLF
*(localized-diagnostic-text-field CRLF) ] *(localized-diagnostic-text-field CRLF) ]
[ last-attempt-date-field CRLF ] [ last-attempt-date-field CRLF ]
[ final-log-id-field CRLF ] [ final-log-id-field CRLF ]
[ will-retry-until-field CRLF ] [ will-retry-until-field CRLF ]
*( extension-field CRLF ) *( extension-field CRLF )
; All fields except for "original-recipient-field", ; All fields except for "original-recipient-field",
; "final-recipient-field", "diagnostic-code-field" ; "final-recipient-field", "diagnostic-code-field",
; and "extension-field" remain unchanged from ; and "extension-field" remain unchanged from
; the definition in RFC 3464. ; the definition in RFC 3464.
generic-address =/ utf-8-enc-addr generic-address =/ utf-8-enc-addr
; Only allowed with the "utf-8" address-type. ; Only allowed with the "utf-8" address-type.
; Updates Section 3.2.3 of RFC3798 ; Updates Section 3.2.3 of RFC 3798.
; ;
; This indirectly updates "original-recipient-field" ; This indirectly updates "original-recipient-field"
; and "final-recipient-field" ; and "final-recipient-field".
diagnostic-code-field = diagnostic-code-field =
"Diagnostic-Code" ":" diagnostic-type ";" *text-fixed "Diagnostic-Code" ":" diagnostic-type ";" *text-fixed
localized-diagnostic-text-field = localized-diagnostic-text-field =
"Localized-Diagnostic" ":" Language-Tag ";" *utf8-text "Localized-Diagnostic" ":" Language-Tag ";" *utf8-text
; "Language-Tag" is a language tag as defined in [RFC5646]. ; "Language-Tag" is a language tag as defined in [RFC5646].
extension-field =/ extension-field-name ":" *utf8-text extension-field =/ extension-field-name ":" *utf8-text
; Updates Section 7 of RFC3798 ; Updates Section 7 of RFC3798
text-fixed = %d1-9 / ; Any US-ASCII character except for NUL, text-fixed = %d1-9 / ; Any ASCII character except for NUL,
%d11 / ; CR and LF %d11 / ; CR, and LF.
%d12 / ; See note above about <text-fixed> %d12 / ; See note above about <text-fixed>
%d14-127 %d14-127
utf8-text = text-fixed / UTF8-non-ascii utf8-text = text-fixed / UTF8-non-ascii
UTF8-non-ascii = UTF8-2 / UTF8-3 / UTF8-4 UTF8-non-ascii = UTF8-2 / UTF8-3 / UTF8-4
4.2. The message/global Media Type 4.2. The message/global Media Type
The second type, used for returning the content, is message/global The second type, used for returning the content, is message/global,
which is similar to message/rfc822, except it contains a message with which is similar to message/rfc822, except it contains a message with
UTF-8 headers. This media type is described in UTF-8 headers. This media type is described in [RFC6532].
[I-D.ietf-eai-rfc5335bis].
4.3. The message/global-headers Media Type 4.3. The message/global-headers Media Type
The third type, used for returning the headers, is message/ The third type, used for returning the headers, is message/
global-headers and contains only the UTF-8 header fields of a message global-headers and contains only the UTF-8 header fields of a message
(all lines prior to the first blank line in a UTF8SMTP message). (all lines prior to the first blank line in a SMTPUTF8 message).
Unlike message/global, this body part provides no difficulties for Unlike message/global, this body part provides no difficulties for
the present infrastructure. the present infrastructure.
4.4. Using These Media Types with multipart/report 4.4. Using These Media Types with multipart/report
Note that as far as a multipart/report [RFC3462] container is Note that as far as a multipart/report [RFC6522] container is
concerned, message/global-delivery-status, message/global, and concerned, message/global-delivery-status, message/global, and
message/global-headers MUST be treated as equivalent to message/ message/global-headers MUST be treated as equivalent to message/
delivery-status, message/rfc822, and text/rfc822-headers. That is, delivery-status, message/rfc822, and text/rfc822-headers. That is,
implementations processing multipart/report MUST expect any implementations processing multipart/report MUST expect any
combinations of the 6 media types mentioned above inside a multipart/ combinations of the 6 media types mentioned above inside a multipart/
report media type. report media type.
All three new types will typically use the "8bit" Content-Transfer- All three new types will typically use the "8bit" Content-Transfer-
Encoding. (In the event all content is 7-bit, the equivalent Encoding. (In the event all content is 7-bit, the equivalent
traditional types for delivery status notifications MAY be used. For traditional types for delivery status notifications MAY be used. For
example, if information in message/global-delivery-status part can be example, if information in a message/global-delivery-status part can
represented without any loss of information as message/ be represented without any loss of information as message/
delivery-status, then the message/delivery-status body part may be delivery-status, then the message/delivery-status body part may be
used.) Note that [I-D.ietf-eai-rfc5335bis] relaxed a restriction used.) Note that [RFC6532] relaxed a restriction from MIME [RFC2046]
from MIME [RFC2046] regarding the use of Content-Transfer-Encoding in regarding the use of Content-Transfer-Encoding in new "message"
new "message" subtypes. This specification explicitly allows the use subtypes. This specification explicitly allows the use of Content-
of Content-Transfer-Encoding in message/global-headers and message/ Transfer-Encoding in message/global-headers and message/
global-delivery-status. This is not believed to be problematic as global-delivery-status. This is not believed to be problematic as
these new media types are intended primarily for use by newer systems these new media types are intended primarily for use by newer systems
with full support for 8-bit MIME and UTF-8 headers. with full support for 8-bit MIME and UTF-8 headers.
4.5. Additional Requirements on SMTP Servers 4.5. Additional Requirements on SMTP Servers
If an SMTP server that advertises both UTF8SMTP and DSN needs to If an SMTP server that advertises both SMTPUTF8 and DSN needs to
return an undeliverable UTF8SMTP message, then it has two choices for return an undeliverable SMTPUTF8 message, then it has two choices for
encapsulating the UTF8SMTP message when generating the corresponding encapsulating the SMTPUTF8 message when generating the corresponding
multipart/report: multipart/report:
If the return path SMTP server does not support UTF8SMTP, then the If the return-path SMTP server does not support SMTPUTF8, then the
undeliverable body part and headers MUST be encoded using a 7-bit undeliverable body part and headers MUST be encoded using a 7-bit
Content-Transfer-Encoding such as "base64" or "quoted-printable" Content-Transfer-Encoding such as "base64" or "quoted-printable"
[RFC2045], as detailed in Section 4. [RFC2045], as detailed in Section 4.
Otherwise, "8bit" Content-Transfer-Encoding can be used. Otherwise, "8bit" Content-Transfer-Encoding can be used.
5. UTF-8 Message Disposition Notifications 5. UTF-8 Message Disposition Notifications
Message Disposition Notifications [RFC3798] have a similar design and Message Disposition Notifications [RFC3798] have a similar design and
structure to DSNs. As a result, they use the same basic return structure to DSNs. As a result, they use the same basic return
skipping to change at page 10, line 26 skipping to change at page 10, line 7
second part of the multipart/report uses a new media type, message/ second part of the multipart/report uses a new media type, message/
global-disposition-notification, which has the syntax of message/ global-disposition-notification, which has the syntax of message/
disposition-notification with two modifications. First, the charset disposition-notification with two modifications. First, the charset
for message/global-disposition-notification is UTF-8, and thus any for message/global-disposition-notification is UTF-8, and thus any
field MAY contain UTF-8 characters when appropriate (see the ABNF field MAY contain UTF-8 characters when appropriate (see the ABNF
below). (In particular, the failure-field, the error-field, and the below). (In particular, the failure-field, the error-field, and the
warning-field MAY contain UTF-8. These fields SHOULD be in i-default warning-field MAY contain UTF-8. These fields SHOULD be in i-default
language [RFC2277].) Second, systems generating a message/ language [RFC2277].) Second, systems generating a message/
global-disposition-notification body part (typically a mail user global-disposition-notification body part (typically a mail user
agent) SHOULD use the UTF-8 address type for all addresses containing agent) SHOULD use the UTF-8 address type for all addresses containing
characters outside the US-ASCII repertoire. characters outside the ASCII repertoire.
The MDN specification also defines the Original-Recipient header The MDN specification also defines the "Original-Recipient:" header
field, which is added with a copy of the contents of ORCPT at field, which is added with a copy of the contents of ORCPT at
delivery time. When generating an Original-Recipient header field, a delivery time. When generating an "Original-Recipient:" header
delivery agent writing a UTF-8 header message in native format SHOULD field, a delivery agent writing a UTF-8 header message in native
convert the utf-8-addr-xtext or the utf-8-addr-unitext form of a format SHOULD convert the utf-8-addr-xtext or the utf-8-addr-unitext
UTF-8 address type in the ORCPT parameter to the corresponding utf-8- form of a UTF-8 address type in the ORCPT parameter to the
address form. corresponding utf-8-address form.
The MDN specification also defines the Disposition-Notification-To The MDN specification also defines the "Disposition-Notification-To:"
header field, which is an address header field and thus follows the header field, which is an address header field and thus follows the
same 8-bit rules as other address header fields such as "From" and same 8-bit rules as other address header fields such as "From:" and
"To" when used in a UTF-8 header message. "To:" when used in a UTF-8 header message.
; ABNF for "original-recipient-header", "original-recipient-field", ; ABNF for "original-recipient-header", "original-recipient-field",
; and "final-recipient-field" from RFC 3798 is implicitly updated ; and "final-recipient-field" from RFC 3798 is implicitly updated
; as they use the updated "generic-address" as defined in ; as they use the updated "generic-address" as defined in
; Section 4 of this document. ; Section 4 of this document.
failure-field = "Failure" ":" *utf8-text failure-field = "Failure" ":" *utf8-text
; "utf8-text" is defined in Section 4 of this document. ; "utf8-text" is defined in Section 4 of this document.
error-field = "Error" ":" *utf8-text error-field = "Error" ":" *utf8-text
; "utf8-text" is defined in Section 4 of this document. ; "utf8-text" is defined in Section 4 of this document.
warning-field = "Warning" ":" *utf8-text warning-field = "Warning" ":" *utf8-text
; "utf8-text" is defined in Section 4 of this document. ; "utf8-text" is defined in Section 4 of this document.
6. IANA Considerations 6. IANA Considerations
This specification does not create any new IANA registries. However, This specification does not create any new IANA registries. However,
the following items are registered as a result of this document. the following items have been registered as a result of this
document.
6.1. UTF-8 Mail Address Type Registration 6.1. UTF-8 Mail Address Type Registration
The mail address type registry was created by [RFC3464]. The The mail address type registry was created by [RFC3464]. The
registration template response follows: registration template response follows:
(a) The proposed address-type name. (a) The address-type name.
UTF-8 UTF-8
(b) The syntax for mailbox addresses of this type, specified using (b) The syntax for mailbox addresses of this type, specified using
BNF, regular expressions, ASN.1, or other non-ambiguous language. BNF, regular expressions, ASN.1, or other non-ambiguous language.
See Section 3. See Section 3.
(c) If addresses of this type are not composed entirely of graphic (c) If addresses of this type are not composed entirely of graphic
characters from the US-ASCII repertoire, a specification for how characters from the ASCII repertoire, a specification for how
they are to be encoded as graphic US-ASCII characters in a DSN they are to be encoded as graphic ASCII characters in an
Original-Recipient or Final-Recipient DSN field. "Original-Recipient:" or "Final-Recipient:" DSN field.
This address type has 3 forms (as defined in Section 3): utf-8- This address type has 3 forms (as defined in Section 3):
addr-xtext, utf-8-addr-unitext, and utf-8-address. Only the utf-8-addr-xtext, utf-8-addr-unitext, and utf-8-address. Only
first form is 7-bit safe. the first form is 7-bit safe.
6.2. Update to 'smtp' Diagnostic Type Registration 6.2. Update to 'smtp' Diagnostic Type Registration
The mail diagnostic type registry was created by [RFC3464] and The mail diagnostic type registry was created by [RFC3464] and
updated by [RFC5337] and this specification. The registration for updated by [RFC5337]. This specification replaces [RFC5337]. The
the 'smtp' diagnostic type should be updated to reference RFC XXXX in registration for the 'smtp' diagnostic type has been updated to
addition to [RFC3464] and [RFC5337]. reference RFC 6533 in addition to [RFC3464] and to remove the
reference to [RFC5337].
When the 'smtp' diagnostic type is used in the context of a message/ When the 'smtp' diagnostic type is used in the context of a message/
delivery-status body part, it remains as presently defined. When the delivery-status body part, it remains as presently defined. When the
'smtp' diagnostic type is used in the context of a message/ 'smtp' diagnostic type is used in the context of a message/
global-delivery-status body part, the codes remain the same, but the global-delivery-status body part, the codes remain the same, but the
text portion MAY contain UTF-8 characters. text portion MAY contain UTF-8 characters.
6.3. message/global-headers 6.3. message/global-headers
Type name: message Type name: message
Subtype name: global-headers Subtype name: global-headers
Required parameters: none Required parameters: none
Optional parameters: none Optional parameters: none
Encoding considerations: This media type contains Internationalized Encoding considerations: This media type contains Internationalized
Email Headers [I-D.ietf-eai-rfc5335bis] with no message body. Email Headers [RFC6532] with no message body. Whenever possible,
Whenever possible, the 8-bit content transfer encoding SHOULD be the 8-bit content transfer encoding SHOULD be used. When this
used. When this media type passes through a 7-bit-only SMTP media type passes through a 7-bit-only SMTP infrastructure, it MAY
infrastructure it MAY be encoded with the base64 or quoted- be encoded with the base64 or quoted-printable content transfer
printable content transfer encoding. encoding.
Security considerations: See Section 7. Security considerations: See Section 7.
Interoperability considerations: It is important that this media Interoperability considerations: It is important that this media
type is not converted to a charset other than UTF-8. As a result, type is not converted to a charset other than UTF-8. As a result,
implementations MUST NOT include a charset parameter with this implementations MUST NOT include a charset parameter with this
media type. Although it might be possible to downconvert this media type. Although it might be possible to down-convert this
media type to the text/rfc822-header media type, such conversion media type to the text/rfc822-header media type, such conversion
is discouraged as it loses information. is discouraged as it loses information.
Published specification: RFC XXXX Published specification: RFC 6533
Applications that use this media type: UTF8SMTP servers and email Applications that use this media type: SMTPUTF8 servers and email
clients that support multipart/report generation or parsing. clients that support multipart/report generation or parsing.
Additional information: Additional information:
Magic number(s): none Magic number(s): none
File extension(s): In the event this is saved to a file, the File extension(s): In the event this is saved to a file, the
extension ".u8hdr" is suggested. extension ".u8hdr" is suggested.
Macintosh file type code(s): The 'TEXT' type code is suggested as Macintosh file type code(s): The 'TEXT' type code is suggested as
files of this type are typically used for diagnostic purposes and files of this type are typically used for diagnostic purposes
suitable for analysis in a UTF-8 aware text editor. A uniform and suitable for analysis in a UTF-8-aware text editor. A
type identifier (UTI) of "public.utf8-email-message-header" is uniform type identifier (UTI) of
suggested. This type conforms to "public.utf8-plain-text" and "public.utf8-email-message-header" is suggested. This type
"public.plain-text". conforms to "public.utf8-plain-text" and "public.plain-text".
Person & email address to contact for further information: See the Person & email address to contact for further information: See the
Authors' Addresses section of this document. Authors' Addresses section of this document.
Intended usage: COMMON Intended usage: COMMON
Restrictions on usage: This media type contains textual data in the Restrictions on usage: This media type contains textual data in the
UTF-8 charset. It typically contains octets with the 8th bit set. UTF-8 charset. It typically contains octets with the 8th bit set.
As a result, a transfer encoding is required when a 7-bit As a result, a transfer encoding is required when a 7-bit
transport is used. transport is used.
skipping to change at page 13, line 28 skipping to change at page 13, line 4
Change controller: IETF Standards Process Change controller: IETF Standards Process
6.4. message/global-delivery-status 6.4. message/global-delivery-status
Type name: message Type name: message
Subtype name: global-delivery-status Subtype name: global-delivery-status
Required parameters: none Required parameters: none
Optional parameters: none Optional parameters: none
Encoding considerations: This media type contains delivery status Encoding considerations: This media type contains delivery status
notification attributes in the UTF-8 charset. The 8-bit content notification attributes in the UTF-8 charset. The 8-bit content
transfer encoding MUST be used with this content-type, unless it transfer encoding MUST be used with this content-type, unless it
is sent over a 7-bit transport environment in which case quoted- is sent over a 7-bit transport environment, in which case quoted-
printable or base64 may be necessary. printable or base64 may be necessary.
Security considerations: See Section 7 Security considerations: See Section 7
Interoperability considerations: This media type provides Interoperability considerations: This media type provides
functionality similar to the message/delivery-status content-type functionality similar to the message/delivery-status content-type
for email message return information. Clients of the previous for email message return information. Clients of the previous
format will need to be upgraded to interpret the new format; format will need to be upgraded to interpret the new format;
however, the new media type makes it simple to identify the however, the new media type makes it simple to identify the
difference. difference.
Published specification: RFC XXXX Published specification: RFC 6533
Applications that use this media type: SMTP servers and email Applications that use this media type: SMTP servers and email
clients that support delivery status notification generation or clients that support delivery status notification generation or
parsing. parsing.
Additional information: Additional information:
Magic number(s): none Magic number(s): none
File extension(s): The extension ".u8dsn" is suggested. File extension(s): The extension ".u8dsn" is suggested.
Macintosh file type code(s): A uniform type identifier (UTI) of Macintosh file type code(s): A uniform type identifier (UTI) of
"public.utf8-email-message-delivery-status" is suggested. This "public.utf8-email-message-delivery-status" is suggested. This
type conforms to "public.utf8-plain-text". type conforms to "public.utf8-plain-text".
Person & email address to contact for further information: See the Person & email address to contact for further information: See the
Authors' Addresses section of this document. Authors' Addresses section of this document.
Intended usage: COMMON Intended usage: COMMON
Restrictions on usage: This is expected to be the second part of a Restrictions on usage: This is expected to be the second part of a
multipart/report. multipart/report.
Author: See the Authors' Addresses section of this document. Author: See the Authors' Addresses section of this document.
skipping to change at page 14, line 40 skipping to change at page 14, line 18
Subtype name: global-disposition-notification Subtype name: global-disposition-notification
Required parameters: none Required parameters: none
Optional parameters: none Optional parameters: none
Encoding considerations: This media type contains disposition Encoding considerations: This media type contains disposition
notification attributes in the UTF-8 charset. The 8-bit content notification attributes in the UTF-8 charset. The 8-bit content
transfer encoding MUST be used with this content-type, unless it transfer encoding MUST be used with this content-type, unless it
is sent over a 7-bit transport environment in which case quoted- is sent over a 7-bit transport environment, in which case quoted-
printable or base64 may be necessary. printable or base64 may be necessary.
Security considerations: See Section 7. Security considerations: See Section 7.
Interoperability considerations: This media type provides Interoperability considerations: This media type provides
functionality similar to the message/disposition-notification functionality similar to the message/disposition-notification
content-type for email message disposition information. Clients content-type for email message disposition information. Clients
of the previous format will need to be upgraded to interpret the of the previous format will need to be upgraded to interpret the
new format; however, the new media type makes it simple to new format; however, the new media type makes it simple to
identify the difference. identify the difference.
Published specification: RFC XXXX Published specification: RFC 6533
Applications that use this media type: Email clients or servers that Applications that use this media type: Email clients or servers that
support message disposition notification generation or parsing. support message disposition notification generation or parsing.
Additional information: Additional information:
Magic number(s): none Magic number(s): none
File extension(s): The extension ".u8mdn" is suggested. File extension(s): The extension ".u8mdn" is suggested.
Macintosh file type code(s): A uniform type identifier (UTI) of Macintosh file type code(s): A uniform type identifier (UTI) of
"public.utf8-email-message-disposition-notification" is suggested. "public.utf8-email-message-disposition-notification" is
This type conforms to "public.utf8-plain-text". suggested. This type conforms to "public.utf8-plain-text".
Person & email address to contact for further information: See the Person & email address to contact for further information: See the
Authors' Addresses section of this document. Authors' Addresses section of this document.
Intended usage: COMMON Intended usage: COMMON
Restrictions on usage: This is expected to be the second part of a Restrictions on usage: This is expected to be the second part of a
multipart/report. multipart/report.
Author: See the Authors' Addresses section of this document. Author: See the Authors' Addresses section of this document.
skipping to change at page 16, line 5 skipping to change at page 15, line 31
service attacks against parser coding mistakes. Code reviews of such service attacks against parser coding mistakes. Code reviews of such
parsers are also recommended. parsers are also recommended.
Malicious users of the email system regularly send messages with Malicious users of the email system regularly send messages with
forged envelope return paths, and these messages trigger delivery forged envelope return paths, and these messages trigger delivery
status reports that result in a large amount of unwanted traffic on status reports that result in a large amount of unwanted traffic on
the Internet. Many users choose to ignore delivery status the Internet. Many users choose to ignore delivery status
notifications because they are usually the result of "blowback" from notifications because they are usually the result of "blowback" from
forged messages and thus never notice when messages they sent go forged messages and thus never notice when messages they sent go
undelivered. As a result, support for correlation of delivery status undelivered. As a result, support for correlation of delivery status
and message disposition notification messages with sent-messages has and message disposition notification messages with sent messages has
become a critical feature of mail clients and possibly mail stores if become a critical feature of mail clients and possibly mail stores,
the email infrastructure is to remain reliable. In the short term, if the email infrastructure is to remain reliable. In the short
simply correlating message-IDs may be sufficient to distinguish true term, simply correlating Message-IDs may be sufficient to distinguish
status notifications from those resulting from forged originator true status notifications from those resulting from forged originator
addresses. But in the longer term, including cryptographic signature addresses. But in the longer term, including cryptographic signature
material that can securely associate the status notification with the material that can securely associate the status notification with the
original message is advisable. original message is advisable.
As this specification permits UTF-8 in additional fields, the As this specification permits UTF-8 in additional fields, the
security considerations of UTF-8 [RFC3629] apply. security considerations of UTF-8 [RFC3629] apply.
8. References 8. References
8.1. Normative References 8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in [ASCII] American National Standards Institute (formerly United
RFCs to Indicate Requirement Levels", States of America Standards Institute), "USA Code for
BCP 14, RFC 2119, March 1997. Information Interchange", ANSI X3.4-1968, 1968.
[RFC2277] Alvestrand, H., "IETF Policy on ANSI X3.4-1968 has been replaced by newer versions with
Character Sets and Languages", BCP 18, slight modifications, but the 1968 version remains
RFC 2277, January 1998. definitive for the Internet.
[RFC3461] Moore, K., "Simple Mail Transfer [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Protocol (SMTP) Service Extension for Requirement Levels", BCP 14, RFC 2119, March 1997.
Delivery Status Notifications (DSNs)",
RFC 3461, January 2003.
[RFC3462] Vaudreuil, G., "The Multipart/Report [RFC2277] Alvestrand, H., "IETF Policy on Character Sets and
Content Type for the Reporting of Mail Languages", BCP 18, RFC 2277, January 1998.
System Administrative Messages",
RFC 3462, January 2003.
[RFC3464] Moore, K. and G. Vaudreuil, "An [RFC3461] Moore, K., "Simple Mail Transfer Protocol (SMTP) Service
Extensible Message Format for Delivery Extension for Delivery Status Notifications (DSNs)",
Status Notifications", RFC 3464, RFC 3461, January 2003.
January 2003.
[RFC3629] Yergeau, F., "UTF-8, a transformation [RFC3464] Moore, K. and G. Vaudreuil, "An Extensible Message Format
format of ISO 10646", STD 63, for Delivery Status Notifications", RFC 3464,
RFC 3629, November 2003. January 2003.
[RFC3798] Hansen, T. and G. Vaudreuil, "Message [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
Disposition Notification", RFC 3798, 10646", STD 63, RFC 3629, November 2003.
May 2004.
[RFC5646] Phillips, A. and M. Davis, "Tags for [RFC3798] Hansen, T. and G. Vaudreuil, "Message Disposition
Identifying Languages", BCP 47, Notification", RFC 3798, May 2004.
RFC 5646, September 2009.
[RFC5321] Klensin, J., "Simple Mail Transfer [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Protocol", RFC 5321, October 2008. Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5322] Resnick, P., Ed., "Internet Message [RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
Format", RFC 5322, October 2008. October 2008.
[RFC5234] Crocker, D. and P. Overell, "Augmented [RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322,
BNF for Syntax Specifications: ABNF", October 2008.
STD 68, RFC 5234, January 2008.
[I-D.ietf-eai-rfc5335bis] Yang, A., Steele, S., and N. Freed, [RFC5646] Phillips, A. and M. Davis, "Tags for Identifying
"Internationalized Email Headers", Languages", BCP 47, RFC 5646, September 2009.
draft-ietf-eai-rfc5335bis-13 (work in
progress), October 2011.
[I-D.ietf-eai-rfc5336bis] Yao, J. and W. MAO, "SMTP Extension [RFC6522] Kucherawy, M., Ed., "The Multipart/Report Media Type for
for Internationalized Email", the Reporting of Mail System Administrative Messages", STD
draft-ietf-eai-rfc5336bis-16 (work in 73, RFC 6522, January 2012.
progress), November 2011.
[I-D.ietf-eai-frmwrk-4952bis] Klensin, J. and Y. Ko, "Overview and [RFC6530] Klensin, J. and Y. Ko, "Overview and Framework for
Framework for Internationalized Internationalized Email", RFC 6530, February 2012.
Email",
draft-ietf-eai-frmwrk-4952bis-12 (work [RFC6531] Yao, J. and W. Mao, "SMTP Extension for Internationalized
in progress), October 2011. Email", RFC 6531, February 2012.
[RFC6532] Yang, A., Steele, S., and N. Freed, "Internationalized
Email Headers", RFC 6532, February 2012.
8.2. Informative References 8.2. Informative References
[RFC2045] Freed, N. and N. Borenstein, [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
"Multipurpose Internet Mail Extensions Extensions (MIME) Part One: Format of Internet Message
(MIME) Part One: Format of Internet Bodies", RFC 2045, November 1996.
Message Bodies", RFC 2045,
November 1996.
[RFC2046] Freed, N. and N. Borenstein, [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
"Multipurpose Internet Mail Extensions Extensions (MIME) Part Two: Media Types", RFC 2046,
(MIME) Part Two: Media Types", November 1996.
RFC 2046, November 1996.
[RFC5337] Newman, C. and A. Melnikov, [RFC5337] Newman, C. and A. Melnikov, "Internationalized Delivery
"Internationalized Delivery Status and Status and Disposition Notifications", RFC 5337,
Disposition Notifications", RFC 5337, September 2008.
September 2008.
Appendix A. Changes Since RFC 5337 Appendix A. Changes since RFC 5337
Made changes to move from Experimental to Standards Track. The most Changes were made to move from Experimental to Standards Track. The
significant was the removal of an embedded alternative ASCII address most significant was the removal of an embedded alternative ASCII
within a utf-8-address, and reflections of the ABNF changes in address within a utf-8-address, and the reflections of the ABNF
[I-D.ietf-eai-rfc5336bis]. changes in [RFC6531].
Fixed description of utf-8-addr-xtext and utf-8-addr-unitext. Fixed description of utf-8-addr-xtext and utf-8-addr-unitext.
References to Downgrade and uMailbox removed/fixed. References to Downgrade and uMailbox removed/fixed.
ABNF changes and errata suggested by Alfred Hoenes. ABNF changes and fixed errata submitted by Alfred Hoenes.
Minor changes to MIME type references. Minor changes to MIME type references.
Other minor corrections. Other minor corrections.
Appendix B. Acknowledgements Appendix B. Acknowledgements
Many thanks for input provided by Pete Resnick, James Galvin, Ned Many thanks for input provided by Pete Resnick, James Galvin, Ned
Freed, John Klensin, Harald Alvestrand, Frank Ellermann, SM, Alfred Freed, John Klensin, Harald Alvestrand, Frank Ellermann, SM, Alfred
Hoenes, Kazunori Fujiwara, and members of the EAI WG to help solidify Hoenes, Kazunori Fujiwara, and members of the EAI working group to
this proposal. help solidify this proposal.
Authors' Addresses Authors' Addresses
Tony Hansen (editor) Tony Hansen (editor)
AT&T Laboratories AT&T Laboratories
200 Laurel Ave. 200 Laurel Ave.
Middletown, NJ 07748 Middletown, NJ 07748
USA US
EMail: tony+eaidsn@maillennium.att.com EMail: tony+eaidsn@maillennium.att.com
Chris Newman Chris Newman
Oracle Oracle
800 Royal Oaks 800 Royal Oaks
Monrovia, CA 91016-6347 Monrovia, CA 91016-6347
US US
EMail: chris.newman@oracle.com EMail: chris.newman@oracle.com
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