- Date: Tue, 11 May 2004 12:26:59 +0200
The SMTP specification has an underlying principle that mail should never
be silently lost due to anything other than exceptional events.
What exactly are "exceptional events"? See below.
This is made explicit in section 6.1 of RFC2821, in particular:
If there is a delivery failure after acceptance of a message, the
receiver-SMTP MUST formulate and mail a notification message. This
notification MUST be sent using a null ("<>") reverse path in the
envelope. The recipient of this notification MUST be the address
from the envelope return path (or the Return-Path: line).
What exactly is a "delivery failure"? My spamfilter silently discards
all sorts of messages, but for obvious reasons it's not going to tell
the "higher level" about it, and by consequence no notification is sent.
Should this be regarded an "exceptional event", even though it is often
more the rule than the exception? Or should "delivery" to /dev/null be
regarded as a successful delivery?
Piet
