Technical Summary
This defines a mechanism for tunneling of SMTP (Simple Mail Transfer
Protocol) Message Transfer Priority values through MTAs (Message
Transfer Agents) that don't support the MT-PRIORITY SMTP extension.
Working Group Summary
There are currently no appropriate email-related working groups. The
ADs and AppsAWG chairs considered the document for the Apps Area WG,
but decided that it would be done best as an individual submission,
and did not need the attention of the working group.
Document Quality
There is at least one prototype implementation, and plans for at least
one other after publication. This is largely being done for a
particular use case, and the proponents are aware of some of the
tradeoffs they've made. The shepherd has some concern about the
broader applicability of this as a standard, given those trade-offs.
That said, some of them had to be made, and there is value in
implementing features from proprietary email systems in standardized
ways on the open Internet. The shepherd supports that general effort.
Personnel
Barry Leiba is the document shepherd
Pete Resnick is the Responsible AD.
RFC Editor note:
Please make the following change to the Introduction:
OLD:
This document is an experimental extension to the SMTP Message
Transfer Priorities extension [SMTP-PRIORITY]. It specifies
application layer tunneling of message priority, to convey the
priority of the messages through Message Transfer Agents (MTAs) that
do not support the Message Transfer Priorities extension. The
tunneling is done by adding a new message header field to Internet
message format specified in [RFC5322].
NEW:
The SMTP Message Transfer Priorities extension [SMTP-PRIORITY]
specifies a mechanism to allow messages to be given a label to
indicate preferential handling, to enable mail handling nodes to take
this into account for onward processing. However, as with all SMTP
extensions, all SMTP Message Transfer Agents (MTAs) between the
source and the destination must support the extension in order for it
to be successfully used. This document describes an application layer
tunneling of message priority, to convey the priority of the messages
through Message Transfer Agents (MTAs) that do not support the
Message Transfer Priorities extension. The tunneling is done by
adding a new message header field to Internet message format
specified in [RFC5322].