idnits 2.17.1 draft-ietf-msgtrk-trkstat-04.txt: ** The Abstract section seems to be numbered Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** Missing expiration date. The document expiration date should appear on the first and last page. ** The document seems to lack a 1id_guidelines paragraph about Internet-Drafts being working documents. ** The document seems to lack a 1id_guidelines paragraph about the list of current Internet-Drafts -- however, there's a paragraph with a matching beginning. Boilerplate error? ** The document seems to lack a 1id_guidelines paragraph about the list of Shadow Directories -- however, there's a paragraph with a matching beginning. Boilerplate error? == No 'Intended status' indicated for this document; assuming Proposed Standard == The page length should not exceed 58 lines per page, but there was 9 longer pages, the longest (page 2) being 62 lines Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an Introduction section. ** There is 1 instance of too long lines in the document, the longest one being 1 character in excess of 72. ** The abstract seems to contain references ([RFC-ESMTP], [RFC-DSN-STAT], [RFC-MIME], [DRAFT-MTRK-SMTPEXT], [RFC-MDN], [DRAFT-MTRK-MTQP], [RFC-DSN-SMTP]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. == The 'Updates: ' line in the draft header should list only the _numbers_ of the RFCs which will be updated by this document (if approved); it should not include the word 'RFC' in the list. Miscellaneous warnings: ---------------------------------------------------------------------------- -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (October 21, 2002) is 7857 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-07) exists of draft-ietf-msgtrk-model-03 ** Downref: Normative reference to an Informational draft: draft-ietf-msgtrk-model (ref. 'DRAFT-MTRK-MODEL') == Outdated reference: A later version (-12) exists of draft-ietf-msgtrk-mtqp-01 == Outdated reference: A later version (-05) exists of draft-ietf-msgtrk-smtpext-04 ** Obsolete normative reference: RFC 2234 (ref. 'RFC-ABNF') (Obsoleted by RFC 4234) ** Obsolete normative reference: RFC 1893 (ref. 'RFC-EMSSC') (Obsoleted by RFC 3463) ** Obsolete normative reference: RFC 2822 (ref. 'RFC-MSGFMT') (Obsoleted by RFC 5322) -- Obsolete informational reference (is this intentional?): RFC 1891 (ref. 'RFC-DSN-SMTP') (Obsoleted by RFC 3461) -- Obsolete informational reference (is this intentional?): RFC 1894 (ref. 'RFC-DSN-STAT') (Obsoleted by RFC 3464) -- Obsolete informational reference (is this intentional?): RFC 1869 (ref. 'RFC-ESMTP') (Obsoleted by RFC 2821) -- Obsolete informational reference (is this intentional?): RFC 2298 (ref. 'RFC-MDN') (Obsoleted by RFC 3798) Summary: 13 errors (**), 0 flaws (~~), 6 warnings (==), 6 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet Draft E. Allman 3 draft-ietf-msgtrk-trkstat-04.txt Sendmail, Inc. 4 Valid for six months October 21, 2002 5 Updates: RFC 1893 7 An Extensible Message Format for Message Tracking Responses 9 11 Status of This Memo 13 This document is an Internet-Draft and is in full conformance 14 with all provisions of Section 10 of RFC2026. Internet-Drafts are 15 working documents of the Internet Engineering Task Force (IETF), its 16 areas, and its working groups. Note that other groups may also 17 distribute working documents as Internet-Drafts. 19 Internet-Drafts are draft documents valid for a maximum of six 20 months and may be updated, replaced, or obsoleted by other documents 21 at any time. It is inappropriate to use Internet-Drafts as reference 22 material or to cite them other than as "work in progress." 24 The IETF takes no position regarding the validity or scope of any 25 intellectual property or other rights that might be claimed to 26 pertain to the implementation or use of the technology described in 27 this document or the extent to which any license under such rights 28 might or might not be available; neither does it represent that it has 29 made any effort to identify any such rights. Information on the 30 IETF's procedures with respect to rights in standards-track and 31 standards-related documentation can be found in BCP-11. Copies of 32 claims of rights made available for publication and any assurances of 33 licenses to be made available, or the result of an attempt made to 34 obtain a general license or permission for the use of such proprietary 35 rights by implementors or users of this specification can be obtained 36 from the IETF Secretariat. 38 The IETF invites any interested party to bring to its attention 39 any copyrights, patents or patent applications, or other proprietary 40 rights which may cover technology that may be required to practice 41 this standard. Please address the information to the IETF Executive 42 Director. 44 The list of current Internet-Drafts can be accessed at: 46 http://www.ietf.org/ietf/1id-abstracts.txt 48 The list of Internet-Draft Shadow Directories can be accessed at: 50 http://www.ietf.org/shadow.html 52 This document is a submission by the MSGTRK Working Group of the 53 Internet Engineering Task Force (IETF). Comments should be submitted 54 to the ietf-msgtrk@imc.org mailing list. An archive of the mailing 55 list may be found at 57 http://www.imc.org/ietf-msgtrk/index.html 59 Distribution of this memo is unlimited. 61 1. Abstract 63 Message Tracking is expected to be used to determine the 64 status of undelivered e-mail upon request. Tracking is used in 65 conjunction with Delivery Status Notifications [RFC-DSN-SMTP] and 66 Message Disposition Notifications [RFC-MDN]; generally, a message 67 tracking request will be issued only when a DSN or MDN has not been 68 received within a reasonable timeout period. 70 This memo defines a MIME [RFC-MIME] content-type for message 71 tracking status in the same spirit as RFC 1894, ``An Extensible 72 Message Format for Delivery Status Notifications'' [RFC-DSN-STAT]. 73 It is to be issued upon a request as described in ``Message 74 Tracking Query Protocol'' [DRAFT-MTRK-MTQP]. This memo defines 75 only the format of the status information. An extension to SMTP 76 [RFC-ESMTP] to label messages for further tracking and request 77 tracking status is defined in a separate memo [DRAFT-MTRK-SMTPEXT]. 79 2. Other Documents and Conformance 81 The model used for Message Tracking is described in [DRAFT- 82 MTRK-MODEL]. 84 Message tracking is intended for use as a "last resort" 85 mechanism. Normally, Delivery Status Notifications (DSNs) [RFC- 86 DSN-SMTP] and Message Disposition Notifications (MDNs) [RFC-MDN] 87 would provide the primary delivery status. Only if no response is 88 received from either of these mechanisms would Message Tracking be 89 used. 91 This document is based on [RFC-DSN-STAT]. Sections 1.3 92 (Terminology), 2.1.1 (General conventions for DSN fields), 2.1.2 93 ("*-type" subfields), and 2.1.3 (Lexical tokens imported from RFC 94 822) of [RFC-DSN-STAT] are included into this document by 95 reference. Other sections are further incorporated as described 96 herein. 98 Syntax notation in this document conforms to [RFC-ABNF]. 100 The following lexical tokens, defined in [RFC-MSGFMT], are 101 used in the ABNF grammar for MTSNs: atom, CHAR, comment, CR, CRLF, 102 DIGIT, LF, linear-white-space, SPACE, text. The date-time lexical 103 token is defined in [RFC-HOSTREQ]. 105 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL 106 NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" 107 in this document are to be interpreted as described in RFC 2119 108 [RFC-KEYWORDS]. 110 3. Format of a Message Tracking Status Notification 112 A Message Tracking Status Notification (MTSN) is intended to 113 be returned as the body of a Message Tracking request [DRAFT-MTRK- 114 MTQP]. The actual body MUST be a multipart/related [RFC-RELATED] 115 with type parameter of "message/tracking-status"; each subpart MUST 116 be of type "message/tracking-status" as described herein. The 117 multipart/related body can include multiple message/tracking-status 118 parts if an MTQP server chains requests to the next server; see 119 [DRAFT-MTRK-MODEL] and [DRAFT-MTRK-MTQP] for more information about 120 chaining. 122 3.1. The message/tracking-status content-type 124 The message/tracking-status content-type is defined as 125 follows: 127 MIME type name: message 128 MIME subtype name: tracking-status 129 Optional parameters: none 130 Encoding considerations: "7bit" encoding is sufficient and 131 MUST be used to maintain readability 132 when viewed by non-MIME mail readers. 133 Security considerations: discussed in section 4 of this memo. 135 The body of a message/tracking-status is modeled after 136 [RFC-DSN-STAT]. That body consists of one or more "fields" 137 formatted to according to the ABNF of RFC 2822 header "fields" 138 (see [RFC-MSGFMT]). The per-message fields appear first, 139 followed by a blank line. Following the per-message fields are 140 one or more groups of per-recipient fields. Each group of per- 141 recipient fields is preceded by a blank line. Note that there 142 will be a blank line between the final per-recipient field and 143 the MIME boundary, since one CRLF is necessary to terminate the 144 field, and a second is necessary to introduce the MIME boundary. 145 Formally, the syntax of the message/tracking-status content is 146 as follows: 148 tracking-status-content = 149 per-message-fields 1*( CRLF per-recipient-fields ) 151 The per-message fields are described in section 3.2. The per- 152 recipient fields are described in section 3.3. 154 3.1.1. General conventions for MTSN fields 156 Section 2.1.1 (General conventions for DSN fields) of 157 [RFC-DSN-STAT] is included herein by reference. Notably, the 158 definition of xtext is identical to that of that document. 160 3.1.2. *-type subfields 162 Section 2.1.2 (*-type subfields) of [RFC-DSN-STAT] is 163 included herein by reference. Notably, the definitions of 164 address-type, diagnostic-type, and MTA-name type are 165 identical to that of RFC 1894. 167 3.2. Per-Message MTSN Fields 169 Some fields of an MTSN apply to all of the addresses in a 170 single envelope. These fields may appear at most once in any 171 MTSN. These fields are used to correlate the MTSN with the 172 original message transaction and to provide additional 173 information which may be useful to gateways. 175 per-message-fields = 176 original-envelope-id-field CRLF 177 reporting-mta-field CRLF 178 arrival-date CRLF 179 *( extension-field CRLF ) 181 3.2.1. The Original-Envelope-Id field 183 The Original-Envelope-Id field is defined as in section 184 2.2.1 of [RFC-DSN-STAT]. This field is REQUIRED. 186 3.2.2. The Reporting-MTA field 188 The Reporting-MTA field is defined as in section 2.2.2 189 of [RFC-DSN-STAT]. This field is REQUIRED. 191 3.2.3. The Arrival-Date field 193 The Arrival-Date field is defined as in section 2.2.5 of 194 [RFC-DSN-STAT]. This field is REQUIRED. 196 3.3. Per-Recipient MTSN fields 198 An MTSN contains information about attempts to deliver a 199 message to one or more recipients. The delivery information for 200 any particular recipient is contained in a group of contiguous 201 per-recipient fields. Each group of per-recipient fields is 202 preceded by a blank line. 204 The syntax for the group of per-recipient fields is as 205 follows: 207 per-recipient-fields = 208 original-recipient-field CRLF 209 final-recipient-field CRLF 210 action-field CRLF 211 status-field CRLF 212 [ remote-mta-field CRLF ] 213 [ last-attempt-date-field CRLF ] 214 [ will-retry-until-field CRLF ] 215 *( extension-field CRLF ) 217 3.3.1. Original-Recipient field 219 The Original-Recipient field is defined as in section 220 2.3.1 of [RFC-DSN-STAT]. This field is REQUIRED. 222 3.3.2. Final-Recipient field 224 The required Final-Recipient field is defined as in 225 section 2.3.2 of [RFC-DSN-STAT]. This field is REQUIRED. 227 3.3.3. Action field 229 The required Action field indicates the action performed 230 by the Reporting-MTA as a result of its attempt to deliver 231 the message to this recipient address. This field MUST be 232 present for each recipient named in the MTSN. The syntax is 233 as defined in section 2.3.3 of RFC 1894. This field is 234 REQUIRED. 236 Valid actions are: 238 failed The message could not be delivered. If DSNs 239 have been enabled, a "failed" DSN should already 240 have been returned. 242 delayed The message is currently waiting in the MTA 243 queue for future delivery. Essentially, this 244 action means "the message is located, and it is 245 here." 247 delivered The message has been successfully delivered to 248 the final recipient. This includes "delivery" 249 to a mailing list exploder. It does not 250 indicate that the message has been read. No 251 further information is available; in particular, 252 the tracking agent SHOULD NOT attempt further 253 "downstream" tracking requests. 255 expanded The message has been successfully delivered to 256 the recipient address as specified by the 257 sender, and forwarded by the Reporting-MTA 258 beyond that destination to multiple additional 259 recipient addresses. However, these additional 260 addresses are not trackable, and the tracking 261 agent SHOULD NOT attempt further "downstream" 262 tracking requests. 264 relayed The message has been delivered into an 265 environment that does not support message 266 tracking. No further information is available; 267 in particular, the tracking agent SHOULD NOT 268 attempt further "downstream" tracking requests. 270 transferred The message has been transferred to another 271 MTRK-compliant MTA. The tracking agent SHOULD 272 attempt further "downstream" tracking requests 273 unless that information is already given in a 274 chaining response. 276 opaque The message may or may not have been seen by 277 this system. No further information is 278 available or forthcoming. 280 There may be some confusion between when to use 281 "expanded" versus "delivered". Whenever possible, "expanded" 282 should be used when the MTA knows that the message will be 283 sent to multiple addresses. However, in some cases the 284 delivery occurs to a program which, unknown to the MTA, 285 causes mailing list expansion; in the extreme case, the 286 delivery may be to a real mailbox that has the side effect of 287 list expansion. If the MTA cannot ensure that this delivery 288 will cause list expansion, it should set the action to 289 "delivered". 291 3.3.4. Status field 293 The Status field is defined as in RFC 1894 section 294 2.3.4. A new code is added to RFC 1893 [RFC-EMSSC], 295 "Enhanced Mail System Status Codes", 297 X.1.9 Message relayed to non-compliant mailer" 299 The mailbox address specified was valid, but the 300 message has been relayed to a system that does not 301 speak this protocol; no further information can be 302 provided. 303 A 2.1.9 Status field MUST be used exclusively with a 304 "relayed" Action field. This field is REQUIRED. 306 3.3.5. Remote-MTA field 308 The Remote-MTA field is defined as in section Reference 309 2.3.5 of [RFC-DSN-STAT]. This field MUST NOT be included if 310 no delivery attempts have been made or if the Action field 311 has value "opaque". If delivery to some agent other than an 312 MTA (for example, a Local Delivery Agent) then this field MAY 313 be included, giving the name of the host on which that agent 314 was contacted. 316 3.3.6. Last-Attempt-Date field 318 The Last-Attempt-Date field is defined as in section 319 Reference 2.3.7 of [RFC-DSN-STAT]. This field is REQUIRED if 320 any delivery attempt has been made and the Action field does 321 not have value "opaque", in which case it will specify when 322 it last attempted to deliver this message to another MTA or 323 other Delivery Agent. This field MUST NOT be included if no 324 delivery attempts have been made. 326 3.3.7. Will-Retry-Until field 328 The Will-Retry-Until field is defined as in section 329 Reference 2.3.8 of [RFC-DSN-STAT]. If the message is not in 330 the local queue or the Action field has the value ``opaque'' 331 the Will-Retry-Until field MUST NOT be included; otherwise, 332 this field SHOULD be included. 334 3.4. Extension fields 336 Future extension fields may be defined as defined in 337 section 2.4 of [RFC-DSN-STAT]. 339 3.5. Interaction Between MTAs and LDAs 341 A message that has been delivered to a Local Delivery Agent 342 (LDA) that understands message tracking (in particular, an LDA 343 speaking LMTP [RFC-LMTP] that supports the MTRK extension) 344 SHOULD pass the tracking request to the LDA. In this case, the 345 Action field for the MTA->LDA exchange will look the same as a 346 transfer to a compliant MTA; that is, a "transferred" tracking 347 status will be issued. 349 4. Security Considerations 351 4.1. Forgery 353 Malicious servers may attempt to subvert message tracking 354 and return false information. This could result in misdirection 355 or misinterpretation of results. 357 4.2. Confidentiality 359 Another dimension of security is confidentiality. There 360 may be cases in which a message recipient is autoforwarding 361 messages but does not wish to divulge the address to which the 362 messages are autoforwarded. The desire for such confidentiality 363 will probably be heightened as "wireless mailboxes", such as 364 pagers, become more widely used as autoforward addresses. 366 MTA authors are encouraged to provide a mechanism which 367 enables the end user to preserve the confidentiality of a 368 forwarding address. Depending on the degree of confidentiality 369 required, and the nature of the environment to which a message 370 were being forwarded, this might be accomplished by one or more 371 of: 373 (a) respond with a "relayed" tracking status when a message is 374 forwarded to a confidential forwarding address, and 375 disabling further message tracking requests. 377 (b) declaring the message to be delivered, issuing a 378 "delivered" tracking status, re-sending the message to the 379 confidential forwarding address, and disabling further 380 message tracking requests. 382 The tracking algorithms MUST NOT allow tracking through 383 list expansions. When a message is delivered to a list, a 384 tracking request MUST respond with an "expanded" tracking status 385 and MUST NOT display the contents of the list. 387 5. IANA Considerations 389 IANA is to register the SMTP extension defined in section 3. 391 6. Acknowledgements 393 Several individuals have commented on and enhanced this draft, 394 including Tony Hansen, Philip Hazel, Alexey Melnikov, Lyndon 395 Nerenberg, Chris Newman, Gregory Neil Shapiro, and Dan Wing. 397 7. Normative References 399 [DRAFT-MTRK-MODEL] 400 T. Hansen, ``Message Tracking Model and Requirements.'' 401 draft-ietf-msgtrk-model-03.txt. November 2000. 403 [DRAFT-MTRK-MTQP] 404 T. Hansen, ``Message Tracking Query Protocol.'' draft-ietf- 405 msgtrk-mtqp-01.txt. November 2000. 407 [DRAFT-MTRK-SMTPEXT] 408 E. Allman, ``SMTP Service Extension for Message Tracking.'' 409 draft-ietf-msgtrk-smtpext-04.txt. October 2002. 411 [RFC-ABNF] 412 Crocker, D., Editor, and P. Overell, ``Augmented BNF for 413 Syntax Specifications: ABNF'', RFC 2234, November 1997. 415 [RFC-EMSSC] 416 G. Vaudreuil, ``Enhanced Mail System Status Codes.'' RFC 417 1893. January 1996. 419 [RFC-HOSTREQ] 420 R. Braden (ed.), ``Requirements for Internet Hosts -- 421 Application and Support.'' STD 3, RFC 1123. October 1989. 423 [RFC-KEYWORDS] 424 S. Bradner, ``Key words for use in RFCs to Indicate 425 Requirement Levels.'' RFC 2119. March 1997. 427 [RFC-MIME] 428 N. Freed and N. Borenstein, ``Multipurpose Internet Mail 429 Extensions (MIME) Part One: Format of Internet Message 430 Bodies.'' RFC 2045. November 1996. 432 [RFC-MSGFMT] 433 P. Resnick, editor, ``Internet Message Format.'' RFC 2822. 434 April 2001. 436 [RFC-RELATED] 437 E. Levinson, ``The MIME Multipart/Related Content-type.'' RFC 438 2387. August 1998. 440 8. Informational References 442 [RFC-DSN-SMTP] 443 K. Moore, ``SMTP Service Extension for Delivery Status 444 Notifications.'' RFC 1891. January 1996. 446 [RFC-DSN-STAT] 447 K. Moore and G. Vaudreuil, ``An Extensible Message Format for 448 Delivery Status Notifications.'' RFC 1894. January 1996. 450 [RFC-ESMTP] 451 Rose, M., Stefferud, E., Crocker, D., Klensin, J. and N. 452 Freed, ``SMTP Service Extensions.'' STD 10, RFC 1869. 453 November 1995. 455 [RFC-LMTP] 456 J. Myers, ``Local Mail Transfer Protocol.'' RFC 2033. 457 October 1996. 459 [RFC-MDN] 460 R. Fajman, ``An Extensible Message Format for Message 461 Disposition Notifications.'' RFC 2298. March 1998. 463 9. Author's Address 465 Eric Allman 466 Sendmail, Inc. 467 6425 Christie Ave, 4th Floor 468 Emeryville, CA 94608 469 U.S.A. 471 E-Mail: eric@Sendmail.COM 472 Phone: +1 510 594 5501 473 Fax: +1 510 594 5429