Greetings,
In the replacement for RFC821 I would like to see the issue clarified
of when it is appropriate to use a null reverse-path. As I understand
RFC821 and also draft-ietf-drums-smtpupd-07, the intended meaning is that
a null reverse-path should only be used in certain circumstances, namely
when an entity A has sent an e-mail message to B, then B may use a null
reverse-path when sending a notification about this message back to A.
What I would like to see clarified is that it is not appropriate to use
a null reverse-path merely because the sender does not want to be
bothered with non-delivery notifications.
Norbert Bollow (Zuerich, Switzerland)
suggested additions to draft-ietf-drums-smtpupd-07
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Add the following at the end of the second paragraph in section 4.1.1.2:
: ... However, a null reverse-path SHOULD NOT be used merely because the
: sender does not want to be bothered with non-delivery notifications. See
: section ##6.4 for a discussion of when a null reverse-path is appropriate
: and when it is not.
Add the following after section 6.3:
: 6.4 The importance of the null reverse-path for debugging mail problems
:
: There are several types of notification messages which are required by
: the relevant standards to be sent with a null reverse path, namely
: non-delivery notifications as discussed in section ##3.7, other kinds
: of Delivery Status Notifications (DSNs, see [RFC 1894]) and also
: Message Disposition Notifications (MDNs, see [RFC 2298]). All of these
: kinds of messages are notification about a previous message, and they
: are sent to the reverse-path of the previous mail message. If the
: delivery of such a notification message fails, that usually indicates
: a problem with the mail system of the host to which the notification
: message is addressed. For this reason, at many hosts the MTA is set up
: to forward such failed notification messages to someone who is able to
: fix problems with the mail system, e.g. via the postmaster alias. This
: is a valuable tool for debugging mail problems.
:
: For messages where the recipient address has been obtained from any
: source other than the reverse-path of a previous message, a null
: reverse path SHOULD NOT be used, so that the mail administrator of the
: destination host will not be needlessly alerted if the message is
: undeliverable.
