7Network Working Group T. Hansen, Ed.
8Request for Comments: 3798 AT&T Laboratories
9Obsoletes: 2298 G. Vaudreuil, Ed.
10Updates: 3461, 2046 Lucent Technologies
11Category: Standards Track May 2004
14 Message Disposition Notification
18 This document specifies an Internet standards track protocol for the
19 Internet community, and requests discussion and suggestions for
20 improvements. Please refer to the current edition of the "Internet
21 Official Protocol Standards" (STD 1) for the standardization state
22 and status of this protocol. Distribution of this memo is unlimited.
26 Copyright (C) The Internet Society (2004). All Rights Reserved.
30 This memo defines a MIME content-type that may be used by a mail user
31 agent (MUA) or electronic mail gateway to report the disposition of a
32 message after it has been successfully delivered to a recipient.
33 This content-type is intended to be machine-processable. Additional
34 message headers are also defined to permit Message Disposition
35 Notifications (MDNs) to be requested by the sender of a message. The
36 purpose is to extend Internet Mail to support functionality often
37 found in other messaging systems, such as X.400 and the proprietary
38 "LAN-based" systems, and often referred to as "read receipts,"
39 "acknowledgements", or "receipt notifications." The intention is to
40 do this while respecting privacy concerns, which have often been
41 expressed when such functions have been discussed in the past.
43 Because many messages are sent between the Internet and other
44 messaging systems (such as X.400 or the proprietary "LAN-based"
45 systems), the MDN protocol is designed to be useful in a multi-
46 protocol messaging environment. To this end, the protocol described
47 in this memo provides for the carriage of "foreign" addresses, in
48 addition to those normally used in Internet Mail. Additional
49 attributes may also be defined to support "tunneling" of foreign
50 notifications through Internet Mail.
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60RFC 3798 Message Disposition Notification May 2004
65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
66 1.1. Purposes . . . . . . . . . . . . . . . . . . . . . . . . 3
67 1.2. Requirements . . . . . . . . . . . . . . . . . . . . . . 3
68 1.3. Terminology. . . . . . . . . . . . . . . . . . . . . . . 4
69 2. Requesting Message Disposition Notifications . . . . . . . . . 4
70 2.1. The Disposition-Notification-To Header . . . . . . . . . 4
71 2.2. The Disposition-Notification-Options Header. . . . . . . 6
72 2.3. The Original-Recipient Header. . . . . . . . . . . . . . 7
73 2.4. Use with the Message/Partial Content Type. . . . . . . . 8
74 3. FORMAT OF A MESSAGE DISPOSITION NOTIFICATION . . . . . . . . . 8
75 3.1. The message/disposition-notification content-type. . . . 9
76 3.2. Message/disposition-notification Fields. . . . . . . . . 11
77 3.3. Extension-fields . . . . . . . . . . . . . . . . . . . . 16
78 4. Timeline of Events . . . . . . . . . . . . . . . . . . . . . . 17
79 5. Conformance and Usage Requirements . . . . . . . . . . . . . . 18
80 6. Security Considerations. . . . . . . . . . . . . . . . . . . . 19
81 6.1. Forgery. . . . . . . . . . . . . . . . . . . . . . . . . 19
82 6.2. Privacy. . . . . . . . . . . . . . . . . . . . . . . . . 19
83 6.3. Non-Repudiation. . . . . . . . . . . . . . . . . . . . . 20
84 6.4. Mail Bombing . . . . . . . . . . . . . . . . . . . . . . 20
85 7. Collected Grammar. . . . . . . . . . . . . . . . . . . . . . . 20
86 8. Guidelines for Gatewaying MDNS . . . . . . . . . . . . . . . . 22
87 8.1. Gatewaying from other mail systems to MDNs . . . . . . . 23
88 8.2. Gatewaying from MDNs to other mail systems . . . . . . . 23
89 8.3. Gatewaying of MDN-requests to other mail systems . . . . 24
90 9. Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
91 10. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 25
92 10.1. Disposition-Notification-Options header parameter names. 26
93 10.2. Disposition modifier names . . . . . . . . . . . . . . . 26
94 10.3. MDN extension field names. . . . . . . . . . . . . . . . 26
95 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 27
96 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27
97 12.1. Normative References . . . . . . . . . . . . . . . . . . 27
98 12.2. Informative References . . . . . . . . . . . . . . . . . 28
99 Appendix A - Changes from RFC 2298 . . . . . . . . . . . . . . . . 29
100 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29
101 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 30
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116RFC 3798 Message Disposition Notification May 2004
121 This memo defines a [RFC-MIME-MEDIA] content-type for message
122 disposition notifications (MDNs). An MDN can be used to notify the
123 sender of a message of any of several conditions that may occur after
124 successful delivery, such as display of the message contents,
125 printing of the message, deletion (without display) of the message,
126 or the recipient's refusal to provide MDNs. The
127 "message/disposition-notification" content-type defined herein is
128 intended for use within the framework of the "multipart/report"
129 content type defined in [RFC-REPORT].
131 This memo defines the format of the notifications and the [RFC-
132 MSGFMT] headers used to request them.
136 The MDNs defined in this memo are expected to serve several purposes:
138 (a) Inform human beings of the disposition of messages after
139 successful delivery, in a manner that is largely independent of
142 (b) Allow mail user agents to keep track of the disposition of
143 messages sent, by associating returned MDNs with earlier message
146 (c) Convey disposition notification requests and disposition
147 notifications between Internet Mail and "foreign" mail systems
150 (d) Allow "foreign" notifications to be tunneled through a MIME-
151 capable message system and back into the original messaging
152 system that issued the original notification, or even to a third
155 (e) Allow language-independent, yet reasonably precise, indications
156 of the disposition of a message to be delivered.
160 These purposes place the following constraints on the notification
163 (a) It must be readable by humans, and must be machine-parsable.
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172RFC 3798 Message Disposition Notification May 2004
175 (b) It must provide enough information to allow message senders (or
176 their user agents) to unambiguously associate an MDN with the
177 message that was sent and the original recipient address for
178 which the MDN was issued (if such information is available),
179 even if the message was forwarded to another recipient address.
181 (c) It must also be able to describe the disposition of a message
182 independent of any particular human language or of the
183 terminology of any particular mail system.
185 (d) The specification must be extensible in order to accommodate
190 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
191 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
192 document are to be interpreted as described in [RFC-KEYWORDS].
194 All syntax descriptions use the ABNF specified by [RFC-MSGFMT], in
195 which the lexical tokens (used below) are defined: "atom", "CRLF",
196 "mailbox", "msg-id", and "text". The following lexical tokens are
197 defined in the definition of the Content-Type header in [RFC-MIME-
198 BODY]: "attribute" and "value".
2002. Requesting Message Disposition Notifications
202 Message disposition notifications are requested by including a
203 Disposition-Notification-To header in the message. Further
204 information to be used by the recipient's MUA in generating the MDN
205 may be provided by also including Original-Recipient and/or
206 Disposition-Notification-Options headers in the message.
2082.1. The Disposition-Notification-To Header
210 A request for the receiving user agent to issue message disposition
211 notifications is made by placing a Disposition-Notification-To header
212 into the message. The syntax of the header is
214 mdn-request-header = "Disposition-Notification-To" ":"
215 mailbox *("," mailbox)
217 The presence of a Disposition-Notification-To header in a message is
218 merely a request for an MDN. The recipients' user agents are always
219 free to silently ignore such a request. Alternatively, an explicit
220 denial of the request for information about the disposition of the
221 message may be sent using the "denied" disposition in an MDN.
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228RFC 3798 Message Disposition Notification May 2004
231 An MDN MUST NOT itself have a Disposition-Notification-To header. An
232 MDN MUST NOT be generated in response to an MDN.
234 A user agent MUST NOT issue more than one MDN on behalf of each
235 particular recipient. That is, once an MDN has been issued on behalf
236 of a recipient, no further MDNs may be issued on behalf of that
237 recipient, even if another disposition is performed on the message.
238 However, if a message is forwarded, an MDN may have been issued for
239 the recipient doing the forwarding and the recipient of the forwarded
240 message may also cause an MDN to be generated.
242 While Internet standards normally do not specify the behavior of user
243 interfaces, it is strongly recommended that the user agent obtain the
244 user's consent before sending an MDN. This consent could be obtained
245 for each message through some sort of prompt or dialog box, or
246 globally through the user's setting of a preference. The user might
247 also indicate globally that MDNs are to never be sent or that a
248 "denied" MDN is always sent in response to a request for an MDN.
250 MDNs SHOULD NOT be sent automatically if the address in the
251 Disposition-Notification-To header differs from the address in the
252 Return-Path header (see [RFC-MSGFMT]). In this case, confirmation
253 from the user SHOULD be obtained, if possible. If obtaining consent
254 is not possible (e.g., because the user is not online at the time),
255 then an MDN SHOULD NOT be sent.
257 Confirmation from the user SHOULD be obtained (or no MDN sent) if
258 there is no Return-Path header in the message, or if there is more
259 than one distinct address in the Disposition-Notification-To header.
261 The comparison of the addresses should be done using only the addr-
262 spec (local-part "@" domain) portion, excluding any phrase and route.
263 The comparison MUST be case-sensitive for the local-part and case-
264 insensitive for the domain part.
266 If the message contains more than one Return-Path header, the
267 implementation may pick one to use for the comparison, or treat the
268 situation as a failure of the comparison.
270 The reason for not automatically sending an MDN if the comparison
271 fails or more than one address is specified is to reduce the
272 possibility of mail loops and of MDNs being used for mail bombing.
274 A message that contains a Disposition-Notification-To header SHOULD
275 also contain a Message-ID header as specified in [RFC-MSGFMT]. This
276 will permit automatic correlation of MDNs with their original
277 messages by user agents.
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284RFC 3798 Message Disposition Notification May 2004
287 If the request for message disposition notifications for some
288 recipients and not others is desired, two copies of the message
289 should be sent, one with a Disposition-Notification-To header and one
290 without. Many of the other headers of the message (e.g., To, Cc)
291 will be the same in both copies. The recipients in the respective
292 message envelopes determine for whom message disposition
293 notifications are requested and for whom they are not. If desired,
294 the Message-ID header may be the same in both copies of the message.
295 Note that there are other situations (e.g., Bcc) in which it is
296 necessary to send multiple copies of a message with slightly
297 different headers. The combination of such situations and the need
298 to request MDNs for a subset of all recipients may result in more
299 than two copies of a message being sent, some with a Disposition-
300 Notification-To header and some without.
302 Messages posted to newsgroups SHOULD NOT have a Disposition-
303 Notification-To header.
3052.2. The Disposition-Notification-Options Header
307 Future extensions to this specification may require that information
308 be supplied to the recipient's MUA for additional control over how
309 and what MDNs are generated. The Disposition-Notification-Options
310 header provides an extensible mechanism for such information. The
311 syntax of this header is as follows:
313 Disposition-Notification-Options =
314 "Disposition-Notification-Options" ":"
315 disposition-notification-parameters
317 disposition-notification-parameters = parameter *(";" parameter)
319 parameter = attribute "=" importance "," value *("," value)
321 importance = "required" / "optional"
323 An importance of "required" indicates that interpretation of the
324 parameter is necessary for proper generation of an MDN in response to
325 this request. If an MUA does not understand the meaning of the
326 parameter, it MUST NOT generate an MDN with any disposition type
327 other than "failed" in response to the request. An importance of
328 "optional" indicates that an MUA that does not understand the meaning
329 of this parameter MAY generate an MDN in response anyway, ignoring
330 the value of the parameter.
332 No parameters are defined in this specification. Parameters may be
333 defined in the future by later revisions or extensions to this
334 specification. Parameter attribute names beginning with "X-" will
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340RFC 3798 Message Disposition Notification May 2004
343 never be defined as standard names; such names are reserved for
344 experimental use. MDN parameter names not beginning with "X-" MUST
345 be registered with the Internet Assigned Numbers Authority (IANA) and
346 described in a standards-track RFC or an experimental RFC approved by
347 the IESG. (See Section 10 for a registration form.)
349 If a required parameter is not understood or contains some sort of
350 error, the receiving MUA SHOULD issue an MDN with a disposition type
351 of "failed" (see Section 3.2.6), and include a Failure field (see
352 Section 3.2.7) that further describes the problem. MDNs with the
353 disposition type of "failed" and a "Failure" field MAY also be
354 generated when other types of errors are detected in the parameters
355 of the Disposition-Notification-Options header.
357 However, an MDN with a disposition type of "failed" MUST NOT be
358 generated if the user has indicated a preference that MDNs are not to
359 be sent. If user consent would be required for an MDN of some other
360 disposition type to be sent, user consent SHOULD also be obtained
361 before sending an MDN with a disposition type of "failed".
3632.3. The Original-Recipient Header
365 Since electronic mail addresses may be rewritten while the message is
366 in transit, it is useful for the original recipient address to be
367 made available by the delivering MTA. The delivering MTA may be able
368 to obtain this information from the ORCPT parameter of the SMTP RCPT
369 TO command, as defined in [RFC-SMTP] and [RFC-DSN-SMTP].
371 [RFC-DSN-SMTP] is amended as follows: If the ORCPT information is
372 available, the delivering MTA SHOULD insert an Original-Recipient
373 header at the beginning of the message (along with the Return-Path
374 header). The delivering MTA MAY delete any other Original-Recipient
375 headers that occur in the message. The syntax of this header is as
378 original-recipient-header =
379 "Original-Recipient" ":" address-type ";" generic-address
381 The address-type and generic-address token are as specified in the
382 description of the Original-Recipient field in section 3.2.3.
384 The purpose of carrying the original recipient information and
385 returning it in the MDN is to permit automatic correlation of MDNs
386 with the original message on a per-recipient basis.
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396RFC 3798 Message Disposition Notification May 2004
3992.4. Use with the Message/Partial Content Type
401 The use of the headers Disposition-Notification-To, Disposition-
402 Notification-Options, and Original-Recipient with the MIME
403 message/partial content type ([RFC-MIME-MEDIA]) requires further
406 When a message is segmented into two or more message/partial
407 fragments, the three headers mentioned in the above paragraph SHOULD
408 be placed in the "inner" or "enclosed" message (using the terms of
409 [RFC-MIME-MEDIA]). These headers SHOULD NOT be used in the headers
410 of any of the fragments themselves.
412 When the multiple message/partial fragments are reassembled, the
413 following applies. If these headers occur along with the other
414 headers of a message/partial fragment message, they pertain to an MDN
415 that will be generated for the fragment. If these headers occur in
416 the headers of the "inner" or "enclosed" message (using the terms of
417 [RFC-MIME-MEDIA]), they pertain to an MDN that will be generated for
418 the reassembled message. Section 5.2.2.1 of [RFC-MIME-MEDIA]) is
419 amended to specify that, in addition to the headers specified there,
420 the three headers described in this specification are to be appended,
421 in order, to the headers of the reassembled message. Any occurrences
422 of the three headers defined here in the headers of the initial
423 enclosing message must not be copied to the reassembled message.
4253. Format of a Message Disposition Notification
427 A message disposition notification is a MIME message with a top-level
428 content-type of multipart/report (defined in [RFC-REPORT]). When
429 multipart/report content is used to transmit an MDN:
431 (a) The report-type parameter of the multipart/report content is
432 "disposition-notification".
434 (b) The first component of the multipart/report contains a human-
435 readable explanation of the MDN, as described in [RFC-REPORT].
437 (c) The second component of the multipart/report is of content-type
438 message/disposition-notification, described in section 3.1 of
441 (d) If the original message or a portion of the message is to be
442 returned to the sender, it appears as the third component of the
443 multipart/report. The decision of whether or not to return the
444 message or part of the message is up to the MUA generating the
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452RFC 3798 Message Disposition Notification May 2004
455 MDN. However, in the case of encrypted messages requesting
456 MDNs, encrypted message text MUST be returned, if it is returned
457 at all, only in its original encrypted form.
459 NOTE: For message disposition notifications gatewayed from foreign
460 systems, the headers of the original message may not be available.
461 In this case, the third component of the MDN may be omitted, or it
462 may contain "simulated" [RFC-MSGFMT] headers that contain equivalent
463 information. In particular, it is very desirable to preserve the
464 subject and date fields from the original message.
466 The MDN MUST be addressed (in both the message header and the
467 transport envelope) to the address(es) from the Disposition-
468 Notification-To header from the original message for which the MDN is
471 The From field of the message header of the MDN MUST contain the
472 address of the person for whom the message disposition notification
475 The envelope sender address (i.e., SMTP MAIL FROM) of the MDN MUST be
476 null (<>), specifying that no Delivery Status Notification messages
477 or other messages indicating successful or unsuccessful delivery are
478 to be sent in response to an MDN.
480 A message disposition notification MUST NOT itself request an MDN.
481 That is, it MUST NOT contain a Disposition-Notification-To header.
483 The Message-ID header (if present) for an MDN MUST be different from
484 the Message-ID of the message for which the MDN is being issued.
486 A particular MDN describes the disposition of exactly one message for
487 exactly one recipient. Multiple MDNs may be generated as a result of
488 one message submission, one per recipient. However, due to the
489 circumstances described in Section 2.1, MDNs may not be generated for
490 some recipients for which MDNs were requested.
4923.1. The message/disposition-notification content-type
494 The message/disposition-notification content-type is defined as
497 MIME type name: message
499 MIME subtype name: disposition-notification
501 Optional parameters: none
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508RFC 3798 Message Disposition Notification May 2004
511 Encoding considerations: "7bit" encoding is sufficient and
512 MUST be used to maintain readability
513 when viewed by non-MIME mail readers.
515 Security considerations: discussed in section 6 of this memo.
517 The message/disposition-notification report type for use in the
518 multipart/report is "disposition-notification".
520 The body of a message/disposition-notification consists of one or
521 more "fields" formatted according to the ABNF of [RFC-MSGFMT] header
522 "fields". The syntax of the message/disposition-notification content
525 disposition-notification-content = [ reporting-ua-field CRLF ]
526 [ mdn-gateway-field CRLF ]
527 [ original-recipient-field CRLF ]
528 final-recipient-field CRLF
529 [ original-message-id-field CRLF ]
530 disposition-field CRLF
531 *( failure-field CRLF )
532 *( error-field CRLF )
533 *( warning-field CRLF )
534 *( extension-field CRLF )
5363.1.1. General conventions for fields
538 Since these fields are defined according to the rules of [RFC-
539 MSGFMT], the same conventions for continuation lines and comments
540 apply. Notification fields may be continued onto multiple lines by
541 beginning each additional line with a SPACE or HTAB. Text that
542 appears in parentheses is considered a comment and not part of the
543 contents of that notification field. Field names are case-
544 insensitive, so the names of notification fields may be spelled in
545 any combination of upper and lower case letters. Comments in
546 notification fields may use the "encoded-word" construct defined in
5493.1.2. "*-type" subfields
551 Several fields consist of a "-type" subfield, followed by a semi-
552 colon, followed by "*text". For these fields, the keyword used in
553 the address-type or MTA-type subfield indicates the expected format
554 of the address or MTA-name that follows.
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564RFC 3798 Message Disposition Notification May 2004
567 The "-type" subfields are defined as follows:
569 (a) An "address-type" specifies the format of a mailbox address.
570 For example, Internet Mail addresses use the "rfc822" address-
575 (b) An "MTA-name-type" specifies the format of a mail transfer agent
576 name. For example, for an SMTP server on an Internet host, the
577 MTA name is the domain name of that host, and the "dns" MTA-
582 Values for address-type and mta-name-type are case-insensitive.
583 Thus, address-type values of "RFC822" and "rfc822" are equivalent.
585 The Internet Assigned Numbers Authority (IANA) maintains a registry
586 of address-type and mta-name-type values, along with descriptions of
587 the meanings of each, or a reference to one or more specifications
588 that provide such descriptions. (The "rfc822" address-type is
589 defined in [RFC-DSN-SMTP].) Registration forms for address-type and
590 mta-name-type appear in [RFC-DSN-FORMAT].
5923.2. Message/disposition-notification Fields
5943.2.1. The Reporting-UA field
596 reporting-ua-field = "Reporting-UA" ":" ua-name
603 The Reporting-UA field is defined as follows:
605 An MDN describes the disposition of a message after it has been
606 delivered to a recipient. In all cases, the Reporting-UA is the MUA
607 that performed the disposition described in the MDN. This field is
608 optional, but recommended. For Internet Mail user agents, it is
609 recommended that this field contain both: the DNS name of the
610 particular instance of the MUA that generated the MDN, and the name
611 of the product. For example,
613 Reporting-UA: pc.example.com; Foomail 97.1
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620RFC 3798 Message Disposition Notification May 2004
623 If the reporting MUA consists of more than one component (e.g., a
624 base program and plug-ins), this may be indicated by including a list
6273.2.2. The MDN-Gateway field
629 The MDN-Gateway field indicates the name of the gateway or MTA that
630 translated a foreign (non-Internet) message disposition notification
631 into this MDN. This field MUST appear in any MDN that was translated
632 by a gateway from a foreign system into MDN format, and MUST NOT
635 mdn-gateway-field = "MDN-Gateway" ":" mta-name-type ";" mta-name
639 For gateways into Internet Mail, the MTA-name-type will normally be
640 "smtp", and the mta-name will be the Internet domain name of the
6433.2.3. Original-Recipient field
645 The Original-Recipient field indicates the original recipient address
646 as specified by the sender of the message for which the MDN is being
647 issued. For Internet Mail messages, the value of the Original-
648 Recipient field is obtained from the Original-Recipient header from
649 the message for which the MDN is being generated. If there is no
650 Original-Recipient header in the message, then the Original-Recipient
651 field MUST be omitted, unless the same information is reliably
652 available some other way. If there is an Original-Recipient header
653 in the original message (or original recipient information is
654 reliably available some other way), then the Original-Recipient field
655 must be supplied. If there is more than one Original-Recipient
656 header in the message, the MUA may choose the one to use, or act as
657 if no Original-Recipient header is present.
659 original-recipient-field =
660 "Original-Recipient" ":" address-type ";"
663 generic-address = *text
665 The address-type field indicates the type of the original recipient
666 address. If the message originated within the Internet, the
667 address-type field will normally be "rfc822", and the address will be
668 according to the syntax specified in [RFC-MSGFMT]. The value
669 "unknown" should be used if the Reporting MUA cannot determine the
670 type of the original recipient address from the message envelope.
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676RFC 3798 Message Disposition Notification May 2004
679 This address is the same as that provided by the sender and can be
680 used to automatically correlate MDN reports with original messages on
681 a per recipient basis.
6833.2.4. Final-Recipient field
685 The Final-Recipient field indicates the recipient for which the MDN
686 is being issued. This field MUST be present.
688 The syntax of the field is as follows:
690 final-recipient-field =
691 "Final-Recipient" ":" address-type ";" generic-address
693 The generic-address subfield of the Final-Recipient field MUST
694 contain the mailbox address of the recipient (from the From header of
695 the MDN) as it was when the MDN was generated by the MUA.
697 The Final-Recipient address may differ from the address originally
698 provided by the sender, because it may have been transformed during
699 forwarding and gatewaying into a totally unrecognizable mess.
700 However, in the absence of the optional Original-Recipient field, the
701 Final-Recipient field and any returned content may be the only
702 information available with which to correlate the MDN with a
703 particular message recipient.
705 The address-type subfield indicates the type of address expected by
706 the reporting MTA in that context. Recipient addresses obtained via
707 SMTP will normally be of address-type "rfc822".
709 Since mailbox addresses (including those used in the Internet) may be
710 case sensitive, the case of alphabetic characters in the address MUST
7133.2.5. Original-Message-ID field
715 The Original-Message-ID field indicates the message-ID of the message
716 for which the MDN is being issued. It is obtained from the Message-
717 ID header of the message for which the MDN is issued. This field
718 MUST be present if the original message contained a Message-ID
719 header. The syntax of the field is as follows:
721 original-message-id-field =
722 "Original-Message-ID" ":" msg-id
724 The msg-id token is as specified in [RFC-MSGFMT].
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732RFC 3798 Message Disposition Notification May 2004
7353.2.6. Disposition field
737 The Disposition field indicates the action performed by the
738 Reporting-MUA on behalf of the user. This field MUST be present.
740 The syntax for the Disposition field is:
743 "Disposition" ":" disposition-mode ";"
745 [ "/" disposition-modifier
746 *( "," disposition-modifier ) ]
748 disposition-mode = action-mode "/" sending-mode
750 action-mode = "manual-action" / "automatic-action"
752 sending-mode = "MDN-sent-manually" / "MDN-sent-automatically"
754 disposition-type = "displayed"
757 disposition-modifier = "error"
758 / disposition-modifier-extension
760 disposition-modifier-extension = atom
762 The disposition-mode, disposition-type, and disposition-modifier may
763 be spelled in any combination of upper and lower case characters.
7653.2.6.1. Disposition modes
767 The following disposition modes are defined:
769 "manual-action" The disposition described by the disposition
770 type was a result of an explicit instruction
771 by the user rather than some sort of
772 automatically performed action.
774 "automatic-action" The disposition described by the disposition
775 type was a result of an automatic action,
776 rather than an explicit instruction by the
777 user for this message.
779 "Manual-action" and "automatic-action" are mutually exclusive. One
780 or the other MUST be specified.
786Hansen & Vaudreuil Standards Track [Page 14]
788RFC 3798 Message Disposition Notification May 2004
791 "MDN-sent-manually" The user explicitly gave permission for this
792 particular MDN to be sent.
794 "MDN-sent-automatically"
795 The MDN was sent because the MUA had
796 previously been configured to do so
799 "MDN-sent-manually" and "MDN-sent-automatically" are mutually
800 exclusive. One or the other MUST be specified.
8023.2.6.2. Disposition types
804 The following disposition-types are defined:
806 "displayed" The message has been displayed by the MUA
807 to someone reading the recipient's mailbox.
808 There is no guarantee that the content has
809 been read or understood.
811 "deleted" The message has been deleted. The
812 recipient may or may not have seen the
813 message. The recipient might "undelete"
814 the message at a later time and read the
8173.2.6.3. Disposition modifiers
819 Only the extension disposition modifiers is defined:
821 disposition-modifier-extension
822 Disposition modifiers may be defined
823 in the future by later revisions
824 or extensions to this specification.
825 Disposition value names beginning with "X-"
826 will never be defined as standard values;
827 such names are reserved for experimental
828 use. MDN disposition value names NOT
829 beginning with "X-" MUST be registered with
830 the Internet Assigned Numbers Authority
831 (IANA) and described in a standards-track
832 RFC or an experimental RFC approved by the
833 IESG. (See Section 10 for a registration
834 form.) MDNs with disposition modifier
835 names not understood by the receiving MUA
836 MAY be silently ignored or placed in the
842Hansen & Vaudreuil Standards Track [Page 15]
844RFC 3798 Message Disposition Notification May 2004
847 user's mailbox without special
848 interpretation. They MUST not cause any
849 error message to be sent to the sender of
852 If an MUA developer does not wish to register the meanings of such
853 disposition modifier extensions, "X-" modifiers may be used for this
854 purpose. To avoid name collisions, the name of the MUA
855 implementation should follow the "X-", (e.g., "X-Foomail-").
857 It is not required that an MUA be able to generate all of the
858 possible values of the Disposition field.
860 A user agent MUST NOT issue more than one MDN on behalf of each
861 particular recipient. That is, once an MDN has been issued on behalf
862 of a recipient, no further MDNs may be issued on behalf of that
863 recipient, even if another disposition is performed on the message.
864 However, if a message is forwarded, a "dispatched" MDN may be issued
865 for the recipient doing the forwarding and the recipient of the
866 forwarded message may also cause an MDN to be generated.
8683.2.7. Failure, Error, and Warning fields
870 The Failure, Error, and Warning fields are used to supply additional
871 information in the form of text messages when the "failure"
872 disposition type, "error" disposition modifier, and/or the "warning"
873 disposition modifier appear. The syntax is as follows:
875 failure-field = "Failure" ":" *text
877 error-field = "Error" ":" *text
879 warning-field = "Warning" ":" *text
883 Additional MDN fields may be defined in the future by later revisions
884 or extensions to this specification. Extension-field names beginning
885 with "X-" will never be defined as standard fields; such names are
886 reserved for experimental use. MDN field names NOT beginning with
887 "X-" MUST be registered with the Internet Assigned Numbers Authority
888 (IANA) and described in a standards-track RFC or an experimental RFC
889 approved by the IESG. (See Section 10 for a registration form.)
898Hansen & Vaudreuil Standards Track [Page 16]
900RFC 3798 Message Disposition Notification May 2004
903 MDN Extension-fields may be defined for the following reasons:
905 (a) To allow additional information from foreign disposition reports
906 to be tunneled through Internet MDNs. The names of such MDN
907 fields should begin with an indication of the foreign
908 environment name (e.g., X400-Physical-Forwarding-Address).
910 (b) To allow transmission of diagnostic information that is specific
911 to a particular mail user agent (MUA). The names of such MDN
912 fields should begin with an indication of the MUA implementation
913 that produced the MDN (e.g., Foomail-information).
915 If an application developer does not wish to register the meanings of
916 such extension fields, "X-" fields may be used for this purpose. To
917 avoid name collisions, the name of the application implementation
918 should follow the "X-", (e.g., "X-Foomail-Log-ID" or "X-Foomail-EDI-
923 The following timeline shows when various events in the processing of
924 a message and generation of MDNs take place:
926 -- User composes message
928 -- User tells MUA to send message
930 -- MUA passes message to MTA (original recipient information passed
933 -- MTA sends message to next MTA
935 -- Final MTA receives message
937 -- Final MTA delivers message to MUA (possibly generating a DSN)
939 -- MUA performs automatic processing and generates corresponding MDNs
940 ("dispatched", "processed", "deleted", "denied", or "failed"
941 disposition type with "automatic-action" and "MDN-sent-
942 automatically" disposition modes)
944 -- MUA displays list of messages to user
946 -- User selects a message and requests that some action be performed
954Hansen & Vaudreuil Standards Track [Page 17]
956RFC 3798 Message Disposition Notification May 2004
959 -- MUA performs requested action and, with user's permission, sends
960 an appropriate MDN ("displayed", "dispatched", "processed",
961 "deleted", "denied", or "failed" disposition type, with "manual-
962 action" and "MDN-sent-manually" or "MDN-sent-automatically"
965 -- User possibly performs other actions on message, but no further
9685. Conformance and Usage Requirements
970 An MUA or gateway conforms to this specification if it generates MDNs
971 according to the protocol defined in this memo. It is not necessary
972 to be able to generate all of the possible values of the Disposition
975 MUAs and gateways MUST NOT generate the Original-Recipient field of
976 an MDN unless the mail protocols provide the address originally
977 specified by the sender at the time of submission. Ordinary SMTP
978 does not make that guarantee, but the SMTP extension defined in
979 [RFC-DSN-SMTP] permits such information to be carried in the envelope
980 if it is available. The Original-Recipient header defined in this
981 document provides a way for the MTA to pass the original recipient
984 Each sender-specified recipient address may result in more than one
985 MDN. If an MDN is requested for a recipient that is forwarded to
986 multiple recipients of an "alias" (as defined in [RFC-DSN-SMTP],
987 section 6.2.7.3), each of the recipients may issue an MDN.
989 Successful distribution of a message to a mailing list exploder
990 SHOULD be considered the final disposition of the message. A mailing
991 list exploder MAY issue an MDN with a disposition type of "processed"
992 and disposition modes of "automatic-action" and "MDN-sent-
993 automatically" indicating that the message has been forwarded to the
994 list. In this case, the request for MDNs is not propagated to the
997 Alternatively, the mailing list exploder MAY issue no MDN and
998 propagate the request for MDNs to all members of the list. The
999 latter behavior is not recommended for any but small, closely knit
1000 lists, as it might cause large numbers of MDNs to be generated and
1001 may cause confidential subscribers to the list to be revealed. The
1002 mailing list exploder MAY also direct MDNs to itself, correlate them,
1003 and produce a report to the original sender of the message.
1005 This specification places no restrictions on the processing of MDNs
1006 received by user agents or mailing lists.
1010Hansen & Vaudreuil Standards Track [Page 18]
1012RFC 3798 Message Disposition Notification May 2004
10156. Security Considerations
1017 The following security considerations apply when using MDNs:
1021 MDNs may be forged as easily as ordinary Internet electronic mail.
1022 User agents and automatic mail handling facilities (such as mail
1023 distribution list exploders) that wish to make automatic use of MDNs
1024 should take appropriate precautions to minimize the potential damage
1025 from denial-of-service attacks.
1027 Security threats related to forged MDNs include the sending of:
1029 (a) A falsified disposition notification when the indicated
1030 disposition of the message has not actually occurred,
1032 (b) Unsolicited MDNs
1036 Another dimension of security is privacy. There may be cases in
1037 which a message recipient does not wish the disposition of messages
1038 addressed to him to be known, or is concerned that the sending of
1039 MDNs may reveal other sensitive information (e.g., when the message
1040 was read). In this situation, it is acceptable for the MUA to issue
1041 "denied" MDNs or to silently ignore requests for MDNs.
1043 If the Disposition-Notification-To header is passed on unmodified
1044 when a message is distributed to the subscribers of a mailing list,
1045 the subscribers to the list may be revealed to the sender of the
1046 original message by the generation of MDNs.
1048 Headers of the original message returned in part 3 of the
1049 multipart/report could reveal confidential information about host
1050 names and/or network topology inside a firewall.
1052 An unencrypted MDN could reveal confidential information about an
1053 encrypted message, especially if all or part of the original message
1054 is returned in part 3 of the multipart/report. Encrypted MDNs are
1055 not defined in this specification.
1057 In general, any optional MDN field may be omitted if the Reporting
1058 MUA site or user determines that inclusion of the field would impose
1059 too great a compromise of site confidentiality. The need for such
1060 confidentiality must be balanced against the utility of the omitted
1061 information in MDNs.
1066Hansen & Vaudreuil Standards Track [Page 19]
1068RFC 3798 Message Disposition Notification May 2004
1071 In some cases, someone with access to the message stream may use the
1072 MDN request mechanism to monitor the mail reading habits of a target.
1073 If the target is known to generate MDN reports, they could add a
1074 disposition-notification-to field containing the envelope from
1075 address along with a source route. The source route is ignored in
1076 the comparison so the addresses will always match. But if the source
1077 route is honored when the notification is sent, it could direct the
1078 message to some other destination. This risk can be minimized by not
1079 sending MDN's automatically.
1083 MDNs do not provide non-repudiation with proof of delivery. Within
1084 the framework of today's Internet Mail, the MDNs defined in this
1085 document provide valuable information to the mail user; however, MDNs
1086 cannot be relied upon as a guarantee that a message was or was not
1087 seen by the recipient. Even if MDNs are not actively forged, they
1088 may be lost in transit. The recipient may bypass the MDN issuing
1089 mechanism in some manner.
1091 One possible solution for this purpose can be found in RFC 2634
1096 The MDN request mechanism introduces an additional way of mailbombing
1097 a mailbox. The MDN request notification provides an address to which
1098 MDN's should be sent. It is possible for an attacking agent to send
1099 a potentially large set of messages to otherwise unsuspecting third
1100 party recipients with a false "disposition-notification-to:" address.
1101 Automatic, or simplistic processing of such requests would result in
1102 a flood of MDN notifications to the target of the attack. Such an
1103 attack could overrun the capacity of the targeted mailbox and deny
1106 For that reason, MDN's SHOULD NOT be sent automatically where the
1107 "disposition-notification-to:" address is different from the envelope
1108 MAIL FROM address. See section 2.1 for further discussion.
1112 NOTE: The following lexical tokens are defined in [RFC-MSGFMT]:
1113 atom, CRLF, mailbox, msg-id, text. The definitions of attribute and
1114 value are as in the definition of the Content-Type header in [RFC-
1122Hansen & Vaudreuil Standards Track [Page 20]
1124RFC 3798 Message Disposition Notification May 2004
1129 mdn-request-header =
1130 "Disposition-Notification-To" ":"
1131 mailbox *("," mailbox)
1133 Disposition-Notification-Options =
1134 "Disposition-Notification-Options" ":"
1135 disposition-notification-parameters
1137 disposition-notification-parameters =
1138 parameter *(";" parameter)
1140 parameter = attribute "=" importance "," value *("," value)
1142 importance = "required" / "optional"
1144 original-recipient-header =
1145 "Original-Recipient" ":" address-type ";" generic-address
1149 disposition-notification-content =
1150 [ reporting-ua-field CRLF ]
1151 [ mdn-gateway-field CRLF ]
1152 [ original-recipient-field CRLF ]
1153 final-recipient-field CRLF
1154 [ original-message-id-field CRLF ]
1155 disposition-field CRLF
1156 *( failure-field CRLF )
1157 *( error-field CRLF )
1158 *( warning-field CRLF )
1159 *( extension-field CRLF )
1163 mta-name-type = atom
1165 reporting-ua-field = "Reporting-UA" ":" ua-name [ ";" ua-product ]
1171 mdn-gateway-field = "MDN-Gateway" ":" mta-name-type ";" mta-name
1178Hansen & Vaudreuil Standards Track [Page 21]
1180RFC 3798 Message Disposition Notification May 2004
1183 original-recipient-field
1184 = "Original-Recipient" ":" address-type ";"
1187 generic-address = *text
1189 final-recipient-field =
1190 "Final-Recipient" ":" address-type ";" generic-address
1193 "Disposition" ":" disposition-mode ";"
1195 [ "/" disposition-modifier
1196 *( "," disposition-modifier ) ]
1198 disposition-mode = action-mode "/" sending-mode
1200 action-mode = "manual-action" / "automatic-action"
1202 sending-mode = "MDN-sent-manually" / "MDN-sent-automatically"
1204 disposition-type = "displayed"
1207 disposition-modifier = "error" / disposition-modifier-extension
1209 disposition-modifier-extension = atom
1211 original-message-id-field = "Original-Message-ID" ":" msg-id
1213 failure-field = "Failure" ":" *text
1215 error-field = "Error" ":" *text
1217 warning-field = "Warning" ":" *text
1219 extension-field = extension-field-name ":" *text
1221 extension-field-name = atom
12238. Guidelines for Gatewaying MDNs
1225 NOTE: This section provides non-binding recommendations for the
1226 construction of mail gateways that wish to provide semi-transparent
1227 disposition notifications between the Internet and another electronic
1228 mail system. Specific MDN gateway requirements for a particular pair
1229 of mail systems may be defined by other documents.
1234Hansen & Vaudreuil Standards Track [Page 22]
1236RFC 3798 Message Disposition Notification May 2004
12398.1. Gatewaying from other mail systems to MDNs
1241 A mail gateway may issue an MDN to convey the contents of a "foreign"
1242 disposition notification over Internet Mail. When there are
1243 appropriate mappings from the foreign notification elements to MDN
1244 fields, the information may be transmitted in those MDN fields.
1245 Additional information (such as might be needed to tunnel the foreign
1246 notification through the Internet) may be defined in extension MDN
1247 fields. (Such fields should be given names that identify the foreign
1248 mail protocol, e.g., X400-* for X.400 protocol elements).
1250 The gateway must attempt to supply reasonable values for the
1251 Reporting-UA, Final-Recipient, and Disposition fields. These will
1252 normally be obtained by translating the values from the foreign
1253 notification into their Internet-style equivalents. However, some
1254 loss of information is to be expected.
1256 The sender-specified recipient address and the original message-id,
1257 if present in the foreign notification, should be preserved in the
1258 Original-Recipient and Original-Message-ID fields.
1260 The gateway should also attempt to preserve the "final" recipient
1261 address from the foreign system. Whenever possible, foreign protocol
1262 elements should be encoded as meaningful printable ASCII strings.
1264 For MDNs produced from foreign disposition notifications, the name of
1265 the gateway MUST appear in the MDN-Gateway field of the MDN.
12678.2. Gatewaying from MDNs to other mail systems
1269 It may be possible to gateway MDNs from the Internet into a foreign
1270 mail system. The primary purpose of such gatewaying is to convey
1271 disposition information in a form that is usable by the destination
1272 system. A secondary purpose is to allow "tunneling" of MDNs through
1273 foreign mail systems in case the MDN may be gatewayed back into the
1276 In general, the recipient of the MDN (i.e., the sender of the
1277 original message) will want to know, for each recipient: the closest
1278 available approximation to the original recipient address, and the
1279 disposition (displayed, printed, etc.).
1281 If possible, the gateway should attempt to preserve the Original-
1282 Recipient address and Original-Message-ID (if present) in the
1283 resulting foreign disposition report.
1290Hansen & Vaudreuil Standards Track [Page 23]
1292RFC 3798 Message Disposition Notification May 2004
1295 If it is possible to tunnel an MDN through the destination
1296 environment, the gateway specification may define a means of
1297 preserving the MDN information in the disposition reports used by
13008.3. Gatewaying of MDN-requests to other mail systems
1302 By use of the separate disposition-notification-to request header,
1303 this specification offers a richer functionality than most, if not
1304 all, other email systems. In most other email systems, the
1305 notification recipient is identical to the message sender as
1306 indicated in the "from" address. There are two interesting cases
1307 when gatewaying into such systems:
1309 1) If the address in the disposition-notification-to header is
1310 identical to the address in the SMTP "MAIL FROM", the expected
1311 behavior will result, even if the disposition-notification-to
1312 information is lost. Systems should propagate the MDN request.
1314 2) If the address in the disposition-notification-to header is
1315 different from the address in the SMTP "MAIL FROM", gatewaying
1316 into a foreign system without a separate notification address will
1317 result in unintended behavior. This is especially important when
1318 the message arrives via a mailing list expansion software that may
1319 specifically replace the SMTP "MAIL FROM" address with an
1320 alternate address. In such cases, the MDN request should not be
1321 gatewayed and should be silently dropped. This is consistent with
1322 other forms of non-support for MDN.
1326 NOTE: This example is provided as illustration only, and is not
1327 considered part of the MDN protocol specification. If the example
1328 conflicts with the protocol definition above, the example is wrong.
1330 Likewise, the use of *-type subfield names or extension fields in
1331 this example is not to be construed as a definition for those type
1332 names or extension fields.
1334 This is an MDN issued after a message has been displayed to the user
1335 of an Internet Mail user agent.
1337 Date: Wed, 20 Sep 1995 00:19:00 (EDT) -0400
1338 From: Joe Recipient <Joe_Recipient@example.com>
1339 Message-Id: <199509200019.12345@example.com>
1340 Subject: Disposition notification
1341 To: Jane Sender <Jane_Sender@example.org>
1346Hansen & Vaudreuil Standards Track [Page 24]
1348RFC 3798 Message Disposition Notification May 2004
1351 Content-Type: multipart/report; report-type=disposition-notification;
1352 boundary="RAA14128.773615765/example.com"
1354 --RAA14128.773615765/example.com
1356 The message sent on 1995 Sep 19 at 13:30:00 (EDT) -0400 to Joe
1357 Recipient <Joe_Recipient@example.com> with subject "First draft of
1358 report" has been displayed. This is no guarantee that the message
1359 has been read or understood.
1361 --RAA14128.773615765/example.com
1362 content-type: message/disposition-notification
1364 Reporting-UA: joes-pc.cs.example.com; Foomail 97.1
1365 Original-Recipient: rfc822;Joe_Recipient@example.com
1366 Final-Recipient: rfc822;Joe_Recipient@example.com
1367 Original-Message-ID: <199509192301.23456@example.org>
1368 Disposition: manual-action/MDN-sent-manually; displayed
1370 --RAA14128.773615765/example.com
1371 content-type: message/rfc822
1373 [original message optionally goes here]
1375 --RAA14128.773615765/example.com--
137710. IANA Considerations
1379 This document specifies three types of parameters that must be
1380 registered with the Internet Assigned Numbers Authority (IANA).
1382 The forms below are for use when registering a new parameter name for
1383 the Disposition-Notification-Options header, a new disposition
1384 modifier name, or a new MDN extension field. Each piece of
1385 information required by a registration form may be satisfied either
1386 by providing the information on the form itself, or by including a
1387 reference to a published, publicly available specification that
1388 includes the necessary information. IANA MAY reject registrations
1389 because of incomplete registration forms or incomplete
1392 To register, complete the following applicable form and send it via
1393 electronic mail to <IANA@IANA.ORG>.
1402Hansen & Vaudreuil Standards Track [Page 25]
1404RFC 3798 Message Disposition Notification May 2004
140710.1. Disposition-Notification-Options header parameter names
1409 A registration for a Disposition-Notification-Options header
1410 parameter name MUST include the following information:
1412 (a) The proposed parameter name.
1414 (b) The syntax for parameter values, specified using BNF, ABNF,
1415 regular expressions, or other non-ambiguous language.
1417 (c) If parameter values are not composed entirely of graphic
1418 characters from the US-ASCII repertoire, a specification for how
1419 they are to be encoded as graphic US-ASCII characters in a
1420 Disposition-Notification-Options header.
1422 (d) A reference to a standards track RFC or experimental RFC
1423 approved by the IESG that describes the semantics of the
142610.2. Disposition modifier names
1428 A registration for a disposition-modifier name (used in the
1429 Disposition field of a message/disposition-notification) MUST include
1430 the following information:
1432 (a) The proposed disposition-modifier name.
1434 (b) A reference to a standards track RFC or experimental RFC
1435 approved by the IESG that describes the semantics of the
1436 disposition modifier.
143810.3. MDN extension field names
1440 A registration for an MDN extension-field name MUST include the
1441 following information:
1443 (a) The proposed extension field name.
1445 (b) The syntax for extension values, specified using BNF, ABNF,
1446 regular expressions, or other non-ambiguous language.
1448 (c) If extension-field values are not composed entirely of graphic
1449 characters from the US-ASCII repertoire, a specification for how
1450 they are to be encoded as graphic US-ASCII characters in a
1451 Disposition-Notification-Options header.
1458Hansen & Vaudreuil Standards Track [Page 26]
1460RFC 3798 Message Disposition Notification May 2004
1463 (d) A reference to a standards track RFC or experimental RFC
1464 approved by the IESG that describes the semantics of the
1469 This document is an updated version of the original document written
1470 by Roger Fajman. His contributions to the definition of Message
1471 Disposition Notifications are greatly appreciated.
1473 RFC 2298 was based on the Delivery Status Notifications document
1474 [RFC-DSN-FORMAT] by Keith Moore and Greg Vaudreuil. Contributions
1475 were made by members of the IETF Receipt Working Group, including
1476 Harald Alvestrand, Ian Bell, Urs Eppenberger, Claus Andri Faerber,
1477 Ned Freed, Jim Galvin, Carl Hage, Mike Lake, Keith Moore, Paul
1478 Overell, Pete Resnick, and Chuck Shih.
148212.1. Normative References
1484 [RFC-SMTP] Klensin, J., Ed., "Simple Mail Transfer Protocol",
1485 RFC 2821, April 2001.
1487 [RFC-MSGFMT] Resnick, P., Ed., "Internet Message Format", RFC
1490 [RFC-MIME-BODY] Freed, N. and N. Borenstein, "Multipurpose Internet
1491 Mail Extensions (MIME) Part One: Format of Internet
1492 Message Bodies", RFC 2045, November 1996.
1494 [RFC-MIME-MEDIA] Freed, N. and N. Borenstein, "Multipurpose Internet
1495 Mail Extensions (MIME) Part Two: Media Types", RFC
1496 2046, November 1996.
1498 [RFC-MIME-HEADER] Moore, K., "MIME (Multipurpose Internet Mail
1499 Extensions) Part Three: Message Header Extensions
1500 for Non-ASCII Text", RFC 2047, November 1996.
1502 [RFC-REPORT] Vaudreuil, G., "The Multipart/Report Content Type
1503 for the Reporting of Mail System Administrative
1504 Messages", RFC 3462, January 2003.
1506 [RFC-DSN-SMTP] Moore, K., "Simple Mail Transfer Protocol (SMTP)
1507 Service Extension for Delivery Status
1508 Notifications", RFC 3461, January 2003.
1514Hansen & Vaudreuil Standards Track [Page 27]
1516RFC 3798 Message Disposition Notification May 2004
1519 [RFC-DSN-FORMAT] Moore, K., and G. Vaudreuil, "An Extensible Format
1520 for Delivery Status Notifications (DSNs)", RFC
1523 [RFC-KEYWORDS] Bradner, S., "Key Words for Use in RFCs to Indicate
1524 Requirement Levels", BCP 14, RFC 2119, March 1997.
152612.2. Informative References
1528 [SEC-SERVICES] Hoffman, P., Ed., "Enhanced Security Services for
1529 S/MIME", RFC 2634, June 1999.
1570Hansen & Vaudreuil Standards Track [Page 28]
1572RFC 3798 Message Disposition Notification May 2004
1575Appendix A - Changes from RFC 2298
1577 The document has new editors.
1579 The dispositions "denied", and "failed" were removed from the
1580 document reflecting the lack of implementation or usage at this time.
1582 The disposition modifiers "warning", "superseded", "expired",
1583 "mailbox-terminated" have not seen actual implementation. They have
1584 been deleted from this document. The extension modifier, as of yet
1585 unused, has been retained for future extension.
1587 General editorial cleanups include spelling, grammar, and consistency
1590 The document has modified BNF for disposition notification options to
1591 eliminate the need for dummy values where not otherwise needed.
1597 Middletown, NJ 07748
1599 Voice: +1-732-420-8934
1600 EMail: tony+rfc3798@maillennium.att.com
1602 Gregory M. Vaudreuil
1607 Voice: +1 214 823 9325
1608 EMail: GregV@ieee.org
1626Hansen & Vaudreuil Standards Track [Page 29]
1628RFC 3798 Message Disposition Notification May 2004
1631Full Copyright Statement
1633 Copyright (C) The Internet Society (2004). This document is subject
1634 to the rights, licenses and restrictions contained in BCP 78, and
1635 except as set forth therein, the authors retain all their rights.
1637 This document and the information contained herein are provided on an
1638 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
1639 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
1640 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
1641 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
1642 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
1643 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
1645Intellectual Property
1647 The IETF takes no position regarding the validity or scope of any
1648 Intellectual Property Rights or other rights that might be claimed to
1649 pertain to the implementation or use of the technology described in
1650 this document or the extent to which any license under such rights
1651 might or might not be available; nor does it represent that it has
1652 made any independent effort to identify any such rights. Information
1653 on the procedures with respect to rights in RFC documents can be
1654 found in BCP 78 and BCP 79.
1656 Copies of IPR disclosures made to the IETF Secretariat and any
1657 assurances of licenses to be made available, or the result of an
1658 attempt made to obtain a general license or permission for the use of
1659 such proprietary rights by implementers or users of this
1660 specification can be obtained from the IETF on-line IPR repository at
1661 http://www.ietf.org/ipr.
1663 The IETF invites any interested party to bring to its attention any
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1666 this standard. Please address the information to the IETF at ietf-
1671 Funding for the RFC Editor function is currently provided by the
1682Hansen & Vaudreuil Standards Track [Page 30]