draft-ietf-eai-dsn-06.txt   rfc5337.txt 
Network Working Group C. Newman Network Working Group C. Newman
Internet-Draft Sun Microsystems Request for Comments: 5337 Sun Microsystems
Updates: 3461,3464,3798 A. Melnikov, Ed. Updates: 3461,3464,3798 A. Melnikov, Ed.
(if approved) Isode Ltd Category: Experimental Isode Ltd
Intended status: Experimental January 21, 2008 September 2008
Expires: July 24, 2008
Internationalized Delivery Status and Disposition Notifications Internationalized Delivery Status and Disposition Notifications
draft-ietf-eai-dsn-06.txt
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Copyright Notice
Copyright (C) The IETF Trust (2008). This memo defines an Experimental Protocol for the Internet
community. It does not specify an Internet standard of any kind.
Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited.
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 standard operation of an email system. However, the existing Draft Standards
is presently limited to US-ASCII text in the machine readable (RFC 3461, RFC 3462, RFC 3464) are presently limited to US-ASCII text
portions of the protocol. This specification adds a new address type in the machine-readable portions of the protocol. This specification
for international email addresses so an original recipient address adds a new address type for international email addresses so an
with non-US-ASCII characters can be correctly preserved even after original recipient address with non-US-ASCII characters can be
downgrading. This also provides updated content return media types correctly preserved even after downgrading. This also provides
for delivery status notifications and message disposition updated content return media types for delivery status notifications
notifications to support use of the new address type. and message disposition notifications to support use of the new
address type.
This document experimentally extends RFC 3461, RFC 3464 and RFC 3798. This document experimentally extends RFC 3461, RFC 3464, and RFC
3798.
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. Additional requirements on SMTP servers . . . . . . . . . 8 4.1. Additional Requirements on SMTP Servers . . . . . . . . . 8
5. UTF-8 Message Disposition Notifications . . . . . . . . . . . 8 5. UTF-8 Message Disposition Notifications . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
6.1. UTF-8 Mail Address Type Registration . . . . . . . . . . . 9 6.1. UTF-8 Mail Address Type Registration . . . . . . . . . . . 10
6.2. Update to 'smtp' Diagnostic Type Registration . . . . . . 10 6.2. Update to 'smtp' Diagnostic Type Registration . . . . . . 11
6.3. message/global-headers . . . . . . . . . . . . . . . . . . 11 6.3. message/global-headers . . . . . . . . . . . . . . . . . . 11
6.4. message/global-delivery-status . . . . . . . . . . . . . . 12 6.4. message/global-delivery-status . . . . . . . . . . . . . . 12
6.5. message/global-disposition-notification . . . . . . . . . 13 6.5. message/global-disposition-notification . . . . . . . . . 13
7. Security Considerations . . . . . . . . . . . . . . . . . . . 14 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
8.1. Normative References . . . . . . . . . . . . . . . . . . . 15 8.1. Normative References . . . . . . . . . . . . . . . . . . . 15
8.2. Informative References . . . . . . . . . . . . . . . . . . 16 8.2. Informative References . . . . . . . . . . . . . . . . . . 16
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 16 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 17
Appendix B. Changes from -05 . . . . . . . . . . . . . . . . . . 16
Appendix C. Changes from -04 . . . . . . . . . . . . . . . . . . 17
Appendix D. Changes from -03 . . . . . . . . . . . . . . . . . . 17
Appendix E. Changes from -02 . . . . . . . . . . . . . . . . . . 17
Appendix F. Changes from -01 . . . . . . . . . . . . . . . . . . 17
Appendix G. Changes from -00 . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
Intellectual Property and Copyright Statements . . . . . . . . . . 19
1. Introduction 1. Introduction
When an email message is transmitted using the UTF8SMTP When an email message is transmitted using the UTF8SMTP [RFC5336]
[I-D.ietf-eai-smtpext] extension and Internationalized Email Headers extension and Internationalized Email Headers [RFC5335], it is
[I-D.ietf-eai-utf8headers], it is sometimes necessary to return that sometimes necessary to return that message or generate a Message
message or generate a Message Disposition Notification [RFC3798] Disposition Notification (MDN) [RFC3798]. As a message sent to
(MDN). As a message sent to multiple recipients can generate a multiple recipients can generate a status and disposition
status and disposition notification for each recipient, it is helpful notification for each recipient, it is helpful if a client can
if a client can correlate these notifications based on the recipient correlate these notifications based on the recipient address it
address it provided, thus preservation of the original recipient is provided; thus, preservation of the original recipient is important.
important. This specification describes how to preserve the original This specification describes how to preserve the original recipient
recipient and updates the MDN and DSN formats to support the new and updates the MDN and DSN formats to support the new address types.
address types.
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 use the Augmented Backus-Naur Form (ABNF) [RFC4234] The formal syntax use the Augmented Backus-Naur Form (ABNF) [RFC5234]
notation including the core rules defined in Appendix B of RFC 4234 notation including the core rules defined in Appendix B of RFC 5234
and the UTF-8 syntax rules in section 4 of [RFC3629]. [RFC5234] and the UTF-8 syntax rules in Section 4 of [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 [RFC5335] is a new
[I-D.ietf-eai-utf8headers] 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 follows: status notifications is specified at the end of this section.
An SMTP [RFC2821] server which advertises both the UTF8SMTP extension An SMTP [RFC2821] server that advertises both the UTF8SMTP extension
[I-D.ietf-eai-smtpext] and the DSN extension [RFC3461] MUST accept a [RFC5336] and the DSN extension [RFC3461] MUST accept a UTF-8 address
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 which does not advertise UTF8SMTP. SMTP server that does not advertise UTF8SMTP.
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. The first 2 forms are 7-bit safe. and utf-8-address. The first 2 forms are 7-bit safe.
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. I.e. protocols capable of native representation of 8-bit characters. That
the utf-8-address form MUST NOT be used in the ORCPT parameter when is, the utf-8-address form MUST NOT be used in the ORCPT parameter
the SMTP server doesn't advertise support for UTF8SMTP or the SMTP when the SMTP server doesn't advertise support for UTF8SMTP or the
server supports UTF8SMTP, but the address contains US-ASCII SMTP server supports UTF8SMTP, but the address contains US-ASCII
characters not permitted in the ORCPT parameter (e.g. the ORCPT characters not permitted in the ORCPT parameter (e.g., the ORCPT
parameter forbids unencoded SP and the = character); or in a 7-bit parameter forbids unencoded SP and the = character), or in a 7-bit
transport environment including a message/delivery-status Original- transport environment including a message/delivery-status Original-
Recipient or Final-Recipient field. In the former case the utf-8- Recipient or Final-Recipient field. In the former case, the utf-8-
addr-xtext form (see below) MUST be used instead, in the latter case addr-xtext form (see below) MUST be used instead; in the latter case,
the utf-8-addr-unitext form MUST be used. The utf-8-address form MAY the utf-8-addr-unitext form MUST be used. The utf-8-address form MAY
be used in the ORCPT parameter when the SMTP server also advertises be used in the ORCPT parameter when the SMTP server also advertises
support for UTF8SMTP and the address doesn't contain any US-ASCII support for UTF8SMTP and the address doesn't contain any US-ASCII
characters not permitted in the ORCPT parameter. It SHOULD be used characters not permitted in the ORCPT parameter. It SHOULD be used
in a message/global-delivery-status Original-Recipient or Final- in a message/global-delivery-status Original-Recipient or Final-
Recipient DSN field; or in an Original-Recipient header field Recipient DSN field, or in an Original-Recipient header field
[RFC3798] if the message is a UTF8SMTP message. [RFC3798] if the message is a UTF8SMTP 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 using in the ORCPT parameter, the UTF-8 address type requires When using in the ORCPT parameter, the UTF-8 address type requires
that US-ASCII CTLs, SP, \, + and = be encoded using xtext encoding as that US-ASCII CTLs, SP, \, +, and = be encoded using xtext encoding
described in [RFC3461]. This is described by the utf-8-addr-xtext as described in [RFC3461]. This is described by the utf-8-addr-xtext
form in the ABNF below. Unicode characters MAY be included in a form in the ABNF below. Unicode characters MAY be included in a
UTF-8 address type using a "\x{HEXPOINT}" syntax UTF-8 address type using a "\x{HEXPOINT}" syntax
(EmbeddedUnicodeChar), where HEXPOINT is 2 to 6 hexadecimal digits. (EmbeddedUnicodeChar), where HEXPOINT is 2 to 6 hexadecimal digits.
When sending data to a UTF8SMTP capable server, native UTF-8 When sending data to a UTF8SMTP-capable server, native UTF-8
characters SHOULD be used instead of the EmbeddedUnicodeChar syntax characters SHOULD be used instead of the EmbeddedUnicodeChar syntax
described in details below. When sending data to an SMTP server described in details below. When sending data to an SMTP server that
which does not advertise UTF8SMTP, then the EmbeddedUnicodeChar does not advertise UTF8SMTP, then the EmbeddedUnicodeChar syntax MUST
syntax MUST be used instead of UTF-8. be used 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-xtext global-delivery-status Original-Recipient field, the utf-8-addr-xtext
form of the UTF-8 address type SHOULD be converted to the 'utf-8- form of the UTF-8 address type SHOULD be converted to the utf-8-
address' form (see the ABNF below) by removing all xtext encoding address form (see the ABNF below) by removing all xtext encoding
first (which will result in the 'utf-8-addr-unitext' form), followed first (which will result in the utf-8-addr-unitext form), followed by
by removal of the 'unitext' encoding. However, if an address is removal of the unitext encoding. However, if an address is labeled
labeled with the UTF-8 address type but does not conform to utf-8 with the UTF-8 address type but does not conform to utf-8 syntax,
syntax, then it MUST be copied into the message/ then it MUST be copied into the message/global-delivery-status field
global-delivery-status field without alteration. 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. It is hoped encodings should be viewed as a transitional mechanism. It is hoped
that as systems lacking support for UTF8SMTP become less common over that as systems lacking support for UTF8SMTP become less common over
time, these encodings can eventually be phased out. time, these encodings can eventually 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 [RFC4234], 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 = uMailbox [ 1*WSP "<" Mailbox ">" ] utf-8-address = uMailbox [ 1*WSP "<" Mailbox ">" ]
; 'uMailbox' is defined in [I-D.ietf-eai-smtpext]. ; uMailbox is defined in [RFC5336].
; 'Mailbox' is defined in [RFC2821]. ; Mailbox is defined in [RFC2821].
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 = xtext utf-8-addr-xtext = xtext
; xtext is defined in [RFC3461]. ; xtext is defined in [RFC3461].
; When xtext encoding is removed, ; When xtext encoding is removed,
; the syntax MUST conform to ; the syntax MUST conform to
; 'utf-8-addr-unitext'. ; utf-8-addr-unitext.
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
QUCHAR = %x21-2a / %x2c-3c / %x3e-5b / %x5d-7e / QUCHAR = %x21-2a / %x2c-3c / %x3e-5b / %x5d-7e /
UTF8-2 / UTF8-3 / UTF8-4 UTF8-2 / UTF8-3 / UTF8-4
; US-ASCII printable characters except ; US-ASCII printable characters except
; CTLs, SP, '\', '+' and '=', plus ; CTLs, SP, '\', '+' and '=', plus
; other Unicode characters in UTF-8 ; other Unicode characters in UTF-8
EmbeddedUnicodeChar = %x5C.78 "{" HEXPOINT "}" EmbeddedUnicodeChar = %x5C.78 "{" HEXPOINT "}"
; starts with "\x" ; starts with "\x"
skipping to change at page 6, line 9 skipping to change at page 6, line 9
; 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 [RFC3462] 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 DSN format does not permit returning of return. As the present DSN format does not permit returning of
undeliverable UTF8SMTP messages, three new media types are needed. undeliverable UTF8SMTP messages, three new media types are needed.
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 described
in UTF8SMTP [I-D.ietf-eai-smtpext]; the Diagnostic-Code field SHOULD in UTF8SMTP [RFC5336]; the Diagnostic-Code field SHOULD be in
be in i-default language [DEFAULTLANG]. Second, systems generating a i-default language [DEFAULTLANG]. Second, systems generating a
message/global-delivery-status body part SHOULD use the utf-8-address message/global-delivery-status body part SHOULD use the utf-8-address
form of the UTF-8 address type for all addresses containing form of the UTF-8 address type for all addresses containing
characters outside the US-ASCII repertoire. These systems SHOULD up- characters outside the US-ASCII repertoire. These systems SHOULD up-
convert the utf-8-addr-xtext or the utf-8-addr-unitext form of a convert the utf-8-addr-xtext or the utf-8-addr-unitext form of a
UTF-8 address type in the ORCPT parameter to the utf-8-address form UTF-8 address type in the ORCPT parameter to the utf-8-address form
of a UTF-8 address type in the Original-Recipient field. Third, a of a UTF-8 address type in the Original-Recipient field. Third, a
new optional field called Localized-Diagnostic is added. Each new optional field called Localized-Diagnostic is added. Each
instance includes a language tag [LANGTAGS] and contains text in the instance includes a language tag [LANGTAGS] 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 MUST
use different language tags. The ABNF for message/ 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 [RFC4234], in section 4 of [RFC3629] or in defined in Appendix B of [RFC5234], in Section 4 of [RFC3629], or in
[RFC3464]. [RFC3464].
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 ]
skipping to change at page 7, line 31 skipping to change at page 7, line 40
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 [LANGTAGS]. ; "Language-Tag" is a language tag as defined in [LANGTAGS].
extension-field =/ extension-field-name ":" *utf8-text extension-field =/ extension-field-name ":" *utf8-text
text-fixed = %d1-9 / ; Any Unicode character except for NUL, text-fixed = %d1-9 / ; Any Unicode character except for NUL,
%d11 / ; CR and LF, encoded in UTF-8 %d11 / ; CR and LF, encoded in UTF-8
%d12 / %d12 /
%d14-127 %d14-127
; Same as <text> from RFC 2822, but without <obs-text>. ; Same as <text> from [RFC2822], but without <obs-text>.
; If/when RFC 2822 is updated to disallow <obs-text>, ; If/when RFC 2822 is updated to disallow <obs-text>,
; this should become just <text> ; this should become just <text>
; Also, if/when RFC 2822 is updated to disallow control characters ; Also, if/when RFC 2822 is updated to disallow control characters
; this should become a reference to RFC 2822upd instead. ; this should become a reference to RFC 2822upd instead.
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
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 [RFC5335].
[I-D.ietf-eai-utf8headers].
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 UTF8SMTP message).
Unlike message/global, this body part provides no difficulties for Unlike message/global, this body part provides no difficulties for
present infrastructure. the present infrastructure.
Note, that as far as multipart/report [RFC3462] container is Note that as far as multipart/report [RFC3462] 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. I.e. 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 MIME types mentioned above inside a multipart/ combinations of the 6 MIME types mentioned above inside a multipart/
report MIME type. report MIME 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 message/global-delivery-status part can be
represented without any loss of information as message/ 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-utf8headers] relaxed restriction from used.) Note that [RFC5335] relaxed restriction from MIME [RFC2046]
MIME [RFC2046] regarding use of Content-Transfer-Encoding in new regarding use of Content-Transfer-Encoding in new "message" subtypes.
"message" subtypes. This specification explicitly allows use of This specification explicitly allows use of Content-Transfer-Encoding
Content-Transfer-Encoding in message/global-headers and message/ in message/global-headers and message/global-delivery-status. This
global-delivery-status. This is not believed to be problematic as is not believed to be problematic as these new MIME types are
these new MIME types are intended primarily for use by newer systems intended primarily for use by newer systems with full support for
with full support for 8-bit MIME and UTF-8 headers. 8-bit MIME and UTF-8 headers.
4.1. Additional requirements on SMTP servers 4.1. Additional Requirements on SMTP Servers
If an SMTP server which advertises both UTF8SMTP and DSN needs to If an SMTP server that advertises both UTF8SMTP and DSN needs to
return an undeliverable UTF8SMTP message, then it MUST NOT downgrade return an undeliverable UTF8SMTP message, then it MUST NOT downgrade
[I-D.ietf-eai-downgrade] the UTF8SMTP message when generating the [DOWNGRADE] the UTF8SMTP message when generating the corresponding
corresponding multipart/report. If the return path SMTP server does multipart/report. If the return path SMTP server does not support
not support UTF8SMTP, then the undeliverable body part and headers UTF8SMTP, then the undeliverable body part and headers MUST be
MUST be encoded using a 7 bit Content-Transfer-Encoding such as encoded using a 7-bit Content-Transfer-Encoding such as "base64" or
base64 or quoted-printable [RFC2045], as detailed in Section 4. "quoted-printable" [RFC2045], as detailed in Section 4. Otherwise,
Otherwise 8bit Content-Transfer-Encoding can be used. "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
format. When generating a MDN for a UTF-8 header message, the third format. When generating an MDN for a UTF-8 header message, the third
part of the multipart/report contains the returned content (message/ part of the multipart/report contains the returned content (message/
global) or header (message/global-headers), same as for DSNs. The global) or header (message/global-headers), same as for DSNs. The
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 [DEFAULTLANG].) Second, systems generating a message/ language [DEFAULTLANG].) 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 US-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 delivery field, which is added with a copy of the contents of ORCPT at
time. When generating an Original-Recipient header field, a delivery delivery time. When generating an Original-Recipient header field, a
agent writing a UTF-8 header message in native format SHOULD convert delivery agent writing a UTF-8 header message in native format SHOULD
the utf-8-addr-xtext or the utf-8-addr-unitext form of a UTF-8 convert the utf-8-addr-xtext or the utf-8-addr-unitext form of a
address type in the ORCPT parameter to the corresponding utf-8- UTF-8 address type in the ORCPT parameter to the corresponding utf-8-
address form. address form.
The MDN specification also defines the Disposition-Notification-To The MDN specification also defines the Disposition-Notification-To
header which is an address header and thus follows the same 8-bit header, which is an address header and thus follows the same 8-bit
rules as other address headers such as "From" and "To" when used in a rules as other address headers such as "From" and "To" when used in a
UTF-8 header message. 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 RFC 3464. The The mail address type registry was created by RFC 3464. The
registration template response follows: registration template response follows:
(a) The proposed address-type name. (a) The proposed 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 they characters from the US-ASCII repertoire, a specification for how
are to be encoded as graphic US-ASCII characters in a DSN Original- they are to be encoded as graphic US-ASCII characters in a DSN
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-addr- This address type has 3 forms (as defined in Section 3): utf-8-
xtext, utf-8-addr-unitext and utf-8-address. The first 2 forms are addr-xtext, utf-8-addr-unitext, and utf-8-address. The first 2
7-bit safe. forms are 7-bit safe.
The utf-8-address form MUST NOT be used 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 support for UTF8SMTP;
2. or the SMTP server supports UTF8SMTP, but the address contains 2. or the SMTP server supports UTF8SMTP, but the address contains
US-ASCII characters not permitted in the ORCPT parameter (e.g. US-ASCII characters not permitted in the ORCPT parameter (e.g.,
the ORCPT parameter forbids SP and the = characters); the ORCPT parameter forbids SP and the = characters);
3. or in a 7-bit transport environment including a message/ 3. or in a 7-bit transport environment including a message/
delivery-status Original-Recipient or Final-Recipient field. delivery-status Original-Recipient or Final-Recipient field.
The utf-8-addr-xtext form MUST be used instead in the first case, the The utf-8-addr-xtext form MUST be used instead in the first case; the
utf-8-addr-unitext form MUST be used in the other two cases. The utf-8-addr-unitext form MUST be used in the other two cases. The
utf-8-address form MAY be used in the ORCPT parameter when the SMTP utf-8-address form MAY be used in the ORCPT parameter when the SMTP
server also advertises support for UTF8SMTP and the address doesn't server also advertises support for UTF8SMTP and the address doesn't
contain any US-ASCII characters not permitted in the ORCPT parameter; contain any US-ASCII characters not permitted in the ORCPT parameter;
in a message/global-delivery-status Original-Recipient or Final- in a message/global-delivery-status Original-Recipient or Final-
Recipient DSN field; or in an Original-Recipient header field Recipient DSN field; or in an Original-Recipient header field
[RFC3798] if the message is a UTF8SMTP message. [RFC3798] if the message is a UTF8SMTP 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.
6.2. Update to 'smtp' Diagnostic Type Registration 6.2. Update to 'smtp' Diagnostic Type Registration
The mail diagnostic type registry was created by RFC 3464. The The mail diagnostic type registry was created by RFC 3464. The
registration for the 'smtp' diagnostic type should be updated to registration for the 'smtp' diagnostic type should be updated to
reference RFC XXXX in addition to RFC 3464. reference RFC 5337 in addition to RFC 3464.
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-utf8headers] with no message body. Email Headers [RFC5335] 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 this media type is Interoperability considerations: It is important that this media
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 downconvert 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 5337
Applications that use this media type: UTF8SMTP servers and email Applications that use this media type: UTF8SMTP 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 and
suitable for analysis in a UTF-8 aware text editor. A uniform suitable for analysis in a UTF-8 aware text editor. A uniform
type identifier (UTI) of "public.utf8-email-message-header" is type identifier (UTI) of "public.utf8-email-message-header" is
suggested. This type conforms to "public.utf8-plain-text" and suggested. This type conforms to "public.utf8-plain-text" and
"public.plain-text". "public.plain-text".
Person & email address to contact for further information: See the Person & email address to contact for further information: See the
Author's address 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 transport As a result, a transfer encoding is required when a 7-bit
is used. transport is used.
Author: See Author's Address section of this document. Author: See the Authors' Addresses section of this document.
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
skipping to change at page 12, line 36 skipping to change at page 13, line 4
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 5337
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
Author's address 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 Author's Address section of this document. Author: See the Authors' Addresses section of this document.
Change controller: IETF Standards Process Change controller: IETF Standards Process
6.5. message/global-disposition-notification 6.5. message/global-disposition-notification
Type name: message Type name: message
Subtype name: global-disposition-notification Subtype name: global-disposition-notification
Required parameters: none Required parameters: none
skipping to change at page 13, line 36 skipping to change at page 14, line 4
6.5. message/global-disposition-notification 6.5. message/global-disposition-notification
Type name: message Type name: message
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 identify new format; however, the new media type makes it simple to
the difference. identify the difference.
Published specification: RFC XXXX Published specification: RFC 5337
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 suggested.
This type conforms to "public.utf8-plain-text". 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
Author's address 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 Author's Address section of this document. Author: See the Authors' Addresses section of this document.
Change controller: IETF Standards Process Change controller: IETF Standards Process
7. Security Considerations 7. Security Considerations
Automated use of report types without authentication presents several Automated use of report types without authentication presents several
security issues. Forging negative reports presents the opportunity security issues. Forging negative reports presents the opportunity
for denial-of-service attacks when the reports are used for automated for denial-of-service attacks when the reports are used for automated
maintenance of directories or mailing lists. Forging positive maintenance of directories or mailing lists. Forging positive
reports may cause the sender to incorrectly believe a message was reports may cause the sender to incorrectly believe a message was
delivered when it was not. delivered when it was not.
Malicious users can generate report structures designed to trigger Malicious users can generate report structures designed to trigger
coding flaws in report parsers. Report parsers need to use secure coding flaws in report parsers. Report parsers need to use secure
coding techniques to avoid the risk of buffer overflow or denial-of- coding techniques to avoid the risk of buffer overflow or denial-of-
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 if
the email infrastructure is to remain reliable. In the short term, the email infrastructure is to remain reliable. In the short term,
simply correlating message-IDs may be sufficient to distinguish true simply correlating message-IDs may be sufficient to distinguish true
status notifications from those resulting from forged originator status notifications from those resulting from forged originator
skipping to change at page 15, line 25 skipping to change at page 15, line 46
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 RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2821] Klensin, J., "Simple Mail Transfer Protocol", RFC 2821, [RFC2821] Klensin, J., "Simple Mail Transfer Protocol",
RFC 2821, April 2001.
[RFC2822] Resnick, P., "Internet Message Format", RFC 2822,
April 2001. April 2001.
[RFC3461] Moore, K., "Simple Mail Transfer Protocol (SMTP) Service [RFC3461] Moore, K., "Simple Mail Transfer Protocol (SMTP)
Extension for Delivery Status Notifications (DSNs)", Service Extension for Delivery Status Notifications
RFC 3461, January 2003. (DSNs)", RFC 3461, January 2003.
[RFC3462] Vaudreuil, G., "The Multipart/Report Content Type for the [RFC3462] Vaudreuil, G., "The Multipart/Report Content Type for
Reporting of Mail System Administrative Messages", the Reporting of Mail System Administrative Messages",
RFC 3462, January 2003. RFC 3462, January 2003.
[RFC3464] Moore, K. and G. Vaudreuil, "An Extensible Message Format [RFC3464] Moore, K. and G. Vaudreuil, "An Extensible Message
for Delivery Status Notifications", RFC 3464, Format for Delivery Status Notifications", RFC 3464,
January 2003. January 2003.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003. 10646", STD 63, RFC 3629, November 2003.
[RFC3798] Hansen, T. and G. Vaudreuil, "Message Disposition [RFC3798] Hansen, T. and G. Vaudreuil, "Message Disposition
Notification", RFC 3798, May 2004. Notification", RFC 3798, May 2004.
[RFC4234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 4234, October 2005. Specifications: ABNF", STD 68, RFC 5234, January 2008.
[I-D.ietf-eai-utf8headers] [RFC5335] Yang, A., Ed., "Internationalized Email Headers",
Yang, A., "Internationalized Email Headers", RFC 5335, September 2008.
draft-ietf-eai-utf8headers-08 (work in progress),
April 2007.
[I-D.ietf-eai-smtpext] [RFC5336] Yao, J., Ed. and W. Mao, Ed., "SMTP Extension for
Yao, J. and W. Mao, "SMTP extension for internationalized Internationalized Email Addresses", RFC 5336,
email address", draft-ietf-eai-smtpext-10 (work in September 2008.
progress), November 2007.
[LANGTAGS] [LANGTAGS] Phillips, A. and M. Davis, "Tags for Identifying
Phillips, A. and M. Davis, "Tags for Identifying
Languages", RFC 4646, September 2006. Languages", RFC 4646, September 2006.
[DEFAULTLANG] [DEFAULTLANG] Alvestrand, H., "IETF Policy on Character Sets and
Alvestrand, H., "IETF Policy on Character Sets and
Languages", RFC 2277, January 1998. Languages", RFC 2277, January 1998.
8.2. Informative References 8.2. Informative References
[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet
Extensions (MIME) Part One: Format of Internet Message Mail Extensions (MIME) Part One: Format of Internet
Bodies", RFC 2045, November 1996. Message Bodies", RFC 2045, November 1996.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet
Extensions (MIME) Part Two: Media Types", RFC 2046, Mail Extensions (MIME) Part Two: Media Types",
November 1996. RFC 2046, November 1996.
[I-D.ietf-eai-downgrade] [DOWNGRADE] Fujiwara, K. and Y. Yoneya, "Downgrading mechanism for
Yoneya, Y. and K. Fujiwara, "Downgrading mechanism for Email Address Internationalization", Work in Progress,
Email Address Internationalization (EAI)", July 2008.
draft-ietf-eai-downgrade-05 (work in progress), Mar 2007.
Appendix A. Acknowledgements Appendix A. 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 and Freed, John Klensin, Harald Alvestrand, Frank Ellermann, SM, and
members of the EAI WG to help solidify this proposal. members of the EAI WG to help solidify this proposal.
Appendix B. Changes from -05
Minor ABNF fixed discovered while examining Bill Fenner's ABNF parser
output.
Minor editorial changes from SM.
Appendix C. Changes from -04
Restructured <utf8-text> to be more clear about how it relates to RFC
2822 <text>.
Appendix D. Changes from -03
Addressed editorial comments from Frank Ellermann and
sm+ietf@elandsys.com.
Moved EAI-downgrade to the Informative References.
Updated references.
Deleted the list of open issues.
Fixed IDnits.
Appendix E. Changes from -02
Make the space between UTF-8 and ASCII address mandatory.
Changed all MIME types to be message/global-*.
Clarified that new message/global-* MIME types are semantically
equivalent to the corresponding RFC 3464 MIME types.
Added a requirement not to downgrade non-delivery reports.
Deleted unused RFC 3501 reference and updated other references.
Appendix F. Changes from -01
Cleaned up and tightened ABNF, in particular HEXPOINT.
Extended DSN report syntax to allow for localized version of
diagnostic-code-field.
Added ABNF for the EAI DSN and EAI MDN.
Appendix G. Changes from -00
Added paragraph about use of 8bit Content-Transfer-Encoding for new
message sub-types.
Updated the list of open issues.
Clarified that this document is targeted to become an Experimental
RFC.
Made the EAI downgrade document a normative reference.
Updated ABNF for utf-8-address.
Authors' Addresses Authors' Addresses
Chris Newman Chris Newman
Sun Microsystems Sun Microsystems
3401 Centrelake Dr., Suite 410 800 Royal Oaks
Ontario, CA 91761 Monrovia, CA 91016-6347
US US
Email: chris.newman@sun.com EMail: chris.newman@sun.com
Alexey Melnikov (editor) Alexey Melnikov (editor)
Isode Ltd Isode Ltd
5 Castle Business Village 5 Castle Business Village
36 Station Road 36 Station Road
Hampton, Middlesex TW12 2BX Hampton, Middlesex TW12 2BX
UK UK
Email: Alexey.Melnikov@isode.com EMail: Alexey.Melnikov@isode.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The IETF Trust (2008). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
skipping to change at page 19, line 44 skipping to change at line 750
attempt made to obtain a general license or permission for the use of attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at this standard. Please address the information to the IETF at
ietf-ipr@ietf.org. ietf-ipr@ietf.org.
Acknowledgment
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
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