draft-ietf-appsawg-received-state-04.txt   rfc6729.txt 
Individual submission D. Crocker Internet Engineering Task Force (IETF) D. Crocker
Internet-Draft Brandenburg InternetWorking Request for Comments: 6729 Brandenburg InternetWorking
Intended status: Standards Track M. Kucherawy Category: Standards Track M. Kucherawy
Expires: December 29, 2012 Cloudmark, Inc. ISSN: 2070-1721 Cloudmark, Inc.
June 27, 2012 September 2012
Indicating Email Handling States in Trace Fields Indicating Email Handling States in Trace Fields
draft-ietf-appsawg-received-state-04
Abstract Abstract
This document registers a trace field clause for use in indicating This document registers a trace field clause for use in indicating
transitions between handling queues or processing states, including transitions between handling queues or processing states, including
enacting inter- and intra-host message transitions. This might enacting inter- and intra-host message transitions. This might
include message quarantining, mailing list moderation, timed include message quarantining, mailing list moderation, timed
delivery, queueing for further analysis, content conversion, or other delivery, queuing for further analysis, content conversion, or other
similar causes, as well as optionally identifying normal handling similar causes, as well as optionally identifying normal handling
queues. queues.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
This Internet-Draft will expire on December 29, 2012. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6729.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction ....................................................2
2. Key Words . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Key Words .......................................................3
3. Trace Clause . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Trace Clause ....................................................3
4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Discussion ......................................................6
5. Granularity . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Granularity .....................................................6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6. IANA Considerations .............................................7
6.1. Mail Parameters Additional-registered-clauses 6.1. MAIL Parameters Additional-registered-clauses
Sub-Registry . . . . . . . . . . . . . . . . . . . . . . . 8 Sub-Registry ...............................................7
6.2. Mail Parameters Registered-states Sub-Registry . . . . . . 8 6.2. MAIL Parameters Registered-states Sub-Registry .............7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9 7. Security Considerations .........................................9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8. References .....................................................10
8.1. Normative References . . . . . . . . . . . . . . . . . . . 10 8.1. Normative References ......................................10
8.2. Informative References . . . . . . . . . . . . . . . . . . 10 8.2. Informative References ....................................10
Appendix A. Trace Field Examples . . . . . . . . . . . . . . . . 10 Appendix A. Trace Field Examples .................................11
A.1. Typical Delivery Without Obvious Extra Handling . . . . . 11 A.1. Typical Delivery without Obvious Extra Handling ...........11
A.2. Delivery With Moderation . . . . . . . . . . . . . . . . . 11 A.2. Delivery with Moderation ..................................11
Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 12 Appendix B. Acknowledgements .....................................12
1. Introduction 1. Introduction
[SMTP] defines the content of email message trace fields, commonly [SMTP] defines the content of email message trace fields, commonly
the "Received" header field. These are typically used to record an the "Received" header field. These are typically used to record an
audit trail of the path a message follows from origin to destination, audit trail of the path a message follows from origin to destination,
with one such field added each time a message moves from one host to with one such field added each time a message moves from one host to
the next. the next.
Section 3.7.2 of that document mentions that "the most important use Section 3.7.2 of that document mentions that "the most important use
of of Received: lines is for debugging mail faults [...]". of Received: lines is for debugging mail faults [...]".
There are some cases where there may be large time gaps between trace There are some cases where there may be large time gaps between trace
fields. Though this might be caused by transient communication fields. Though this might be caused by transient communication
issues, they might also be caused by policy decisions or special issues, they might also be caused by policy decisions or special
processing regarding the content of the message, authorization of processing regarding the content of the message, authorization of
some identity on the message, or transitions between major software some identity on the message, or transitions between major software
components. Common examples include message quarantines (filters components. Common examples include message quarantines (filters
that cause a message to be held pending further evaluation, or that cause a message to be held pending further evaluation or
delivery of a message pending manual operator action), pending delivery of a message pending manual operator action), pending
content analysis, or mailing list servers that impose moderation content analysis, or mailing list servers that impose moderation
rules (mailing list owner action required regarding mail from authors rules (mailing list owner action required regarding mail from authors
not subscribed to those lists). not subscribed to those lists).
This document registers a new optional clause that can be used in This document registers a new optional clause that can be used in
trace fields to indicate that a message entered such a special trace fields to indicate that a message entered such a special
processing queue or state for some period. This allows inspection of processing queue or state for some period. This allows inspection of
the trace information to reveal that the cause for a time gap in the trace information to reveal that the cause for a time gap in
trace fields was imposed by additional processing rather than one trace fields was imposed by additional processing rather than one
skipping to change at page 3, line 44 skipping to change at page 3, line 21
2. Key Words 2. Key Words
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 [KEYWORDS]. document are to be interpreted as described in [KEYWORDS].
3. Trace Clause 3. Trace Clause
This specification defines a clause, called "state", which MAY be This specification defines a clause, called "state", which MAY be
used when creating a Recevied header field (see Section 4.4 of used when creating a Received header field (see Section 4.4 of
[SMTP]) to indicate the nature of additional handling imposed on the [SMTP]) to indicate the nature of additional handling imposed on the
relaying of a message toward its recipient(s). It is followed by a relaying of a message toward its recipient(s). It is followed by a
single keyword that provides that detail. A Mail Transfer Agent single keyword that provides that detail. A Mail Transfer Agent
(MTA) or other handling agent that determines a message has entered a (MTA) or other handling agent that determines a message has entered a
state other than normal queueing of messages for relaying or delivery state other than normal queuing of messages for relaying or delivery
MAY generate a trace field including one of these clauses. That is, MAY generate a trace field including one of these clauses. That is,
the presence of this clause on a trace field is an indication of the the presence of this clause on a trace field is an indication of the
entry of the message into that state; a later trace field added would entry of the message into that state; a later trace field added would
indicate its departure from that state. indicate its departure from that state.
An MTA implementing this specification SHOULD add a Received field as An MTA implementing this specification SHOULD add a Received field as
described whenever: described whenever:
a. It determines that a special handling condition will occur, and a. It determines that a special handling condition will occur and
places it into that condition; or places it into that condition; or
b. It determines that no special handling is required, and prepares b. It determines that no special handling is required and prepares
it for relay to the next handling agent. it for relay to the next handling agent.
An MTA need not add a Received field indicating preparation for An MTA need not add a Received field indicating preparation for
normal handoff to the next handling agent if it has already added a normal handoff to the next handling agent if it has already added a
Received field for some other reason. Trace data added by the next Received field for some other reason. Trace data added by the next
handling agent will imply the message's exit from the special handling agent will imply the message's exit from the special
handling condition. handling condition.
If a single MTA processes a message through multiple special handling If a single MTA processes a message through multiple special handling
conditions, it MAY add a Received for each distinct condition. conditions, it MAY add a Received field for each distinct condition.
For example: Presume a message will be injected into MTA-1, then For example, presume a message will be injected into MTA-1, then
travel to MTA-3 via MTA-2, and then MTA-3 enacts final delivery. At travel to MTA-3 via MTA-2, and then MTA-3 will enact final delivery.
MTA-2, it is determined that some action will be taken that will At MTA-2, it is determined that some action will be taken that will
cause the message to undergo some handling change that is outside of cause the message to undergo some handling change that is outside of
typical message flow. In this case: typical message flow. In this case:
1. MTA-1 adds a typical Received field and relays it to MTA-2 1. MTA-1 adds a typical Received field and relays it to MTA-2.
2. MTA-2 determines that the atypical handling will occur and adds a 2. MTA-2 determines that the atypical handling will occur and adds a
Received field using the extension specified here Received field using the extension specified here.
3. On completion of the atypical handling, MTA-2 relays the message 3. On completion of the atypical handling, MTA-2 relays the message
to MTA-3 to MTA-3.
4. MTA-3 adds a typical Received field and enacts final delivery of 4. MTA-3 adds a typical Received field and enacts final delivery of
the message the message.
Appropriate use of this mechanism does not include associating meta- Appropriate use of this mechanism does not include associating meta-
data with the message, such as categorizing the message (e.g., the data with the message, such as categorizing the message (e.g., the
notions of "is spam" or "was 8-bit, converted to 7-bit"). Processing notions of "is spam" or "was 8-bit, converted to 7-bit"). Processing
agents also cannot reliably use this mechanism to determine anything agents also cannot reliably use this mechanism to determine anything
about the message content, since there is no guarantee that all about the message content, since there is no guarantee that all
agents in the chain of handling made such annotations allowing agents in the chain of handling made such annotations to allow
correct conclusions. The sole purpose here is to allow one to correct conclusions. The sole purpose here is to allow one to
determine the point(s) in the chain of custody of a message at which determine the point(s) in the chain of custody of a message at which
the message was subjected to handling outside of normal message the message was subjected to handling outside of normal message
routing and queueing. routing and queuing.
The following state keywords are defined in this document; extensions The following state keywords are defined in this document; extensions
may define other registered keywords (see Section 6.2): may define other registered keywords (see Section 6.2):
auth: The message entered a queue pending authentication of some auth: The message entered a queue pending authentication of some
identifier in the message. identifier in the message.
content: The message entered a queue pending content analysis, such content: The message entered a queue pending content analysis, such
as scanning for spam or viruses. as scanning for spam or viruses.
skipping to change at page 5, line 25 skipping to change at page 5, line 6
moderation: The message entered a hold pending mailing list moderation: The message entered a hold pending mailing list
moderator action. moderator action.
normal: The message is not in an administrative hold and is queued normal: The message is not in an administrative hold and is queued
for or is being handed off to the next handling agent (which may for or is being handed off to the next handling agent (which may
be local delivery). This is the default interpretation when no be local delivery). This is the default interpretation when no
"state" clause is present. "state" clause is present.
other: The message entered a hold or queue for reasons not covered other: The message entered a hold or queue for reasons not covered
by other keywords in this list, and not for transient technology by other keywords in this list and not for transient technology
issues. issues.
outbound: The message entered a queue for outbound relaying. This outbound: The message entered a queue for outbound relaying. This
is typically the last case added for a single host, and the next is typically the last case added for a single host, and the next
Received header field is expected to be added by some other host. Received header field is expected to be added by some other host.
quarantine: The message entered a hold in an isolation queue pending quarantine: The message entered a hold in an isolation queue pending
operator action for local policy reasons. operator action for local policy reasons.
timed: The message entered a hold in order to meet a requested timed: The message entered a hold in order to meet a requested
delivery window, such as is defined in [FUTURERELEASE]. delivery window, such as is defined in [FUTURERELEASE].
The "state" clause is added in Section 6 to the Additional- In Section 6, the "state" clause is added to the Additional-
Registered-Clauses IANA sub-registry. The ABNF for this clause is: Registered-Clauses IANA sub-registry. The ABNF for this clause is:
State = CFWS "state" FWS queue-state-keyword [ "/" value ] State = CFWS "state" FWS queue-state-keyword [ "/" value ]
queue-state-keyword = ( reg-state-keyword / unreg-state-keyword ) queue-state-keyword = ( reg-state-keyword / unreg-state-keyword )
reg-state-keyword = ( "auth" / "content" / "convert" / reg-state-keyword = ( "auth" / "content" / "convert" /
"moderation" / "normal" / "other" / "moderation" / "normal" / "other" /
"outbound" / "quarantine" / "timed" / "outbound" / "quarantine" / "timed" /
additional-state-keyword ) additional-state-keyword )
skipping to change at page 7, line 10 skipping to change at page 6, line 28
an outbound queue could add four Received header fields denoting each an outbound queue could add four Received header fields denoting each
of these states. However, where they are all done as part of a of these states. However, where they are all done as part of a
single system process, in a single pass, doing so would be considered single system process, in a single pass, doing so would be considered
unusual (and extremely verbose). This method SHOULD NOT be applied unusual (and extremely verbose). This method SHOULD NOT be applied
except when doing detailed analysis of a single component to identify except when doing detailed analysis of a single component to identify
performance issues with those steps. performance issues with those steps.
Rather, an agent that wishes to make a state annotation SHOULD add Rather, an agent that wishes to make a state annotation SHOULD add
only a single Received header field including such annotation, thus only a single Received header field including such annotation, thus
indicating (a) the time of completion of its handling of the message indicating (a) the time of completion of its handling of the message
via the date portion of the field, and (b) the final disposition of via the date portion of the field and (b) the final disposition of
that message relative to that agent. For example, an MTA receiving a that message relative to that agent. For example, an MTA receiving a
message that performs various checks on the message before message that performs various checks on the message before
immediately handing it off to a Mailing List Manager (MLM) would only immediately handing it off to a Mailing List Manager (MLM) would only
record a "normal" state, assuming it passes those checks. The MLM record a "normal" state, assuming it passes those checks. The MLM
would then evaluate the message and record its own state once it would then evaluate the message and record its own state once it
decides what the next step will be for the handling of that message. decides what the next step will be for the handling of that message.
5. Granularity 5. Granularity
The degree of granularity -- and therefore the degree of verbosity -- The degree of granularity -- and therefore the degree of verbosity --
recorded through the use of this additional trace clause is likely to recorded through the use of this additional trace clause is likely to
vary depending on circumstances. It will typically be the case that vary depending on circumstances. It will typically be the case that
use of this clause will be limited to "unusual" transitions, such as use of this clause will be limited to "unusual" transitions, such as
when a message requires additional scrutiny or other processing, or when a message requires additional scrutiny or other processing or
needs to be quarantined. needs to be quarantined.
Somewhat greater granularity might also include transitions of Somewhat greater granularity might also include transitions of
administrative responsibility, such as between an Mail Transfer Agent administrative responsibility, such as between a Mail Transfer Agent
(MTA) operator and a Mailing List Manager (MLM) operator. This could (MTA) operator and a Mailing List Manager (MLM) operator. This could
be further enhanced to note some transitions that are interesting be further enhanced to note some transitions that are interesting
only when other transitions have occurred, such as noting entry to only when other transitions have occurred, such as noting entry to
the outbound queue only when the message is originating from an the outbound queue only when the message is originating from an
"interesting" source, like an MLM, since an MLM can introduce "interesting" source, like an MLM, since an MLM can introduce
significant changes to the message or delivery delay and it could be significant changes to the message or delivery delay and it could be
useful to know when it completed its processing, as distinct from the useful to know when it completed its processing, as distinct from the
subsequent processing by the originating MTA. In circumstances subsequent processing by the originating MTA. In circumstances
needing very fine-grained trace information, fields might be created needing very fine-grained trace information, fields might be created
to note all of these "significant" network architecture transitions. to note all of these "significant" network architecture transitions.
One should note, however, when choosing higher levels of granularity, One should note, however, when choosing higher levels of granularity,
that the Received header fields present on a message could be counted that the Received header fields present on a message could be counted
by MTAs when trying to decide whether or not a message routing loop by MTAs when trying to decide whether or not a message routing loop
is in effect. A message with an abundance of these might cause an is in effect. A message with an abundance of these might cause an
incorrect determination that the message is in a delivery loop, incorrect determination that the message is in a delivery loop,
causing it to be removed from the mail stream. See Section 6.3 of causing it to be removed from the mail stream. See Section 6.3 of
[SMTP] for further discussion. [SMTP] for further discussion.
6. IANA Considerations 6. IANA Considerations
6.1. Mail Parameters Additional-registered-clauses Sub-Registry
This document adds to the "Additional-registered-clauses" sub- 6.1. MAIL Parameters Additional-registered-clauses Sub-Registry
registry of the "Mail Parameters" registry, created by [SMTP], the
following entry: This document adds the following entry to the "Additional-registered-
clauses" sub-registry of the "MAIL Parameters" registry, created by
[SMTP]:
Clause name: state Clause name: state
Description: Indicates entry into a special queue state Description: Indicates entry into a special queue state
Syntax Summary: state <state-name> Syntax Summary: state <state-name>
Reference: [this document] Reference: [RFC6729]
6.2. Mail Parameters Registered-states Sub-Registry 6.2. MAIL Parameters Registered-states Sub-Registry
The "Mail Parameters" registry at IANA is updated by the creation of The "MAIL Parameters" registry at IANA has been updated by the
the "Registered-states" sub-registry to contain valid state keywords creation of the "Registered-states" sub-registry to contain valid
for use with this specification. Updates to this registry are state keywords for use with this specification. Updates to this
governed by the First Come First Served rules of [IANA] for new registry are governed by the First Come, First Served rules of [IANA]
registrations. Changes to the status of existing entries are limited for new registrations. Changes to the status of existing entries are
to the original registrant or IESG approval. limited to the original registrant or IESG approval.
Discussion of all registry updates is encouraged via one or more IETF Discussion of all registry updates is encouraged via one or more IETF
mailing lists that typically cover email-related subjects prior to mailing lists that typically cover email-related subjects prior to
approval of the change, as a way of documenting the work. The approval of the change, as a way of documenting the work. The
ietf-smtp@ietf.org list is suggested. ietf-smtp@ietf.org list is suggested.
Note that only registrations of queue state keywords are permitted. Note that only registrations of queue state keywords are permitted.
The registry is not to be used for specifying secondary information The registry is not to be used for specifying secondary information
(i.e., the "value" part of the ABNF in Section 3). (i.e., the "value" part of the ABNF in Section 3).
skipping to change at page 9, line 10 skipping to change at page 9, line 10
Use: One of "current" (the state keyword is in current use), Use: One of "current" (the state keyword is in current use),
"deprecated" (the state keyword is in use but not recommended for "deprecated" (the state keyword is in use but not recommended for
new implementations), or "historic" (the state keyword is no new implementations), or "historic" (the state keyword is no
longer in substantial current use). longer in substantial current use).
The initial registration set is as follows: The initial registration set is as follows:
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| Name | Description | Specification | Use | | Name | Description | Specification | Use |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| auth | Held for message | [this document] | current | | auth | Held for message | [RFC6729] | current |
| | authentication | | | | | authentication | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| content | Held for message | [this document] | current | | content | Held for message | [RFC6729] | current |
| | content analysis | | | | | content analysis | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| convert | Held for message | [this document] | current | | convert | Held for message | [RFC6729] | current |
| | content conversion | | | | | content conversion | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| moderation | Held for list | [this document] | current | | moderation | Held for list | [RFC6729] | current |
| | moderation | | | | | moderation | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| normal | Message is not being | [this document] | current | | normal | Message is not being | [RFC6729] | current |
| | held other than to | | | | | held other than to | | |
| | accommodate typical | | | | | accommodate typical | | |
| | relaying handling | | | | | relaying handling | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| other | Held for causes not | [this document] | current | | other | Held for causes not | [RFC6729] | current |
| | covered by other | | | | | covered by other | | |
| | registered state | | | | | registered state | | |
| | keywords | | | | | keywords | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| outbound | Message placed in | [this document] | current | | outbound | Message placed in | [RFC6729] | current |
| | outbound queue | | | | | outbound queue | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| quarantine | Held for operator | [this document] | current | | quarantine | Held for operator | [RFC6729] | current |
| | action due to content | | | | | action due to content | | |
| | analysis or local | | | | | analysis or local | | |
| | policy | | | | | policy | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
| timed | Held to accommodate a | [this document] | current | | timed | Held to accommodate a | [RFC6729] | current |
| | specific requested | | | | | specific requested | | |
| | delivery window | | | | | delivery window | | |
+------------+------------------------+-----------------+---------+ +------------+------------------------+-----------------+---------+
7. Security Considerations 7. Security Considerations
The use of this trace information can reveal hints as to local policy The use of this trace information can reveal hints as to local policy
that was in effect at the time of message handling. that was in effect at the time of message handling.
Further discussion about trace field security can be found in Section Further discussion about trace field security can be found in Section
skipping to change at page 10, line 16 skipping to change at page 10, line 16
8.1. Normative References 8.1. Normative References
[IANA] Narten, T. and H. Alvestrand, "Guidelines for [IANA] Narten, T. and H. Alvestrand, "Guidelines for
Writing an IANA Considerations Section in RFCs", Writing an IANA Considerations Section in RFCs",
BCP 26, RFC 5226, May 2008. BCP 26, RFC 5226, May 2008.
[KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate [KEYWORDS] 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.
[MAIL] Resnick, P., "Internet Message Format", RFC 5322, [MAIL] Resnick, P., Ed., "Internet Message Format",
October 2008. RFC 5322, October 2008.
[MIME] Freed, N. and N. Borenstein, "Simple Mail Transfer [MIME] Freed, N. and N. Borenstein, "Multipurpose Internet
Protocol", RFC 2045, November 1996. Mail Extensions (MIME) Part One: Format of Internet
Message Bodies", RFC 2045, November 1996.
[SMTP] Klensin, J., "Simple Mail Transfer Protocol", [SMTP] Klensin, J., "Simple Mail Transfer Protocol",
RFC 5321, October 2008. RFC 5321, October 2008.
8.2. Informative References 8.2. Informative References
[FUTURERELEASE] White, G. and G. Vaudreuil, "SMTP Submission Service [FUTURERELEASE] White, G. and G. Vaudreuil, "SMTP Submission Service
Extension for Future Message Release", RFC 4865, Extension for Future Message Release", RFC 4865,
May 2007. May 2007.
Appendix A. Trace Field Examples Appendix A. Trace Field Examples
This section includes a sample of the new trace field clause in use. This section includes a sample of the new trace field clause in use.
A.1. Typical Delivery Without Obvious Extra Handling A.1. Typical Delivery without Obvious Extra Handling
Typical message delivery Typical message delivery
Received: from newyork.example.com Received: from newyork.example.com
(newyork.example.com [192.0.2.250]) (newyork.example.com [192.0.2.250])
by mail-router.example.net (8.11.6/8.11.6) by mail-router.example.net (8.11.6/8.11.6)
with ESMTP id i7PK0sH7021929 with ESMTP id i7PK0sH7021929
for <recipient@example.net>; for <recipient@example.net>;
Fri, Feb 15 2002 17:19:22 -0800 Fri, Feb 15 2002 17:19:22 -0800
Received: from internal.example.com Received: from internal.example.com
(internal.example.com [192.168.0.1]) (internal.example.com [192.168.0.1])
by newyork.example.com (8.11.6/8.11.6) by newyork.example.com (8.11.6/8.11.6)
with ESMTP id i9MKZCRd064134 with ESMTP id i9MKZCRd064134
for <recipient@example.net>; for <recipient@example.net>;
Fri, Feb 15 2002 17:19:08 -0800 Fri, Feb 15 2002 17:19:08 -0800
Example 1: Typical message delivery with no appreciable extra Example 1: Typical message delivery with no appreciable extra
handling; only Received header fields shown handling; only Received header fields shown
A.2. Delivery With Moderation A.2. Delivery with Moderation
Message delivery after moderation Message delivery after moderation
Received: from newyork.example.com Received: from newyork.example.com
(newyork.example.com [192.0.2.250]) (newyork.example.com [192.0.2.250])
by mail-router.example.net (8.11.6/8.11.6) by mail-router.example.net (8.11.6/8.11.6)
with ESMTP id i7PK0sH7021929 with ESMTP id i7PK0sH7021929
for <recipient@example.net>; for <recipient@example.net>;
Fri, Feb 15 2002 18:33:29 -0800 Fri, Feb 15 2002 18:33:29 -0800
Received: from internal.example.com Received: from internal.example.com
skipping to change at page 12, line 29 skipping to change at page 12, line 32
USA USA
Phone: +1.408.246.8253 Phone: +1.408.246.8253
EMail: dcrocker@bbiw.net EMail: dcrocker@bbiw.net
URI: http://bbiw.net URI: http://bbiw.net
Murray S. Kucherawy Murray S. Kucherawy
Cloudmark, Inc. Cloudmark, Inc.
128 King St., 2nd Floor 128 King St., 2nd Floor
San Francisco, CA 94107 San Francisco, CA 94107
US USA
EMail: superuser@gmail.com EMail: superuser@gmail.com
 End of changes. 45 change blocks. 
85 lines changed or deleted 83 lines changed or added

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