On Wed, 5 Nov 1997, Chris Bartram wrote:
* most UAs will not have access to the SMTP "MAIL FROM" address anyway,
which is where DSNs are *supposed* to go
This is incorrect. UAs will have access to the "MAIL FROM" address unless
an upstream system violated Internet standards. The final delivery agent
is REQUIRED to copy the "MAIL FROM" address into the "Return-Path"
header. Anything which doesn't is broken.
* even those that do will have to know to ignore (obviously) empty
MAIL FROM addresses - so do implementations that support this action
need exception handlers to deal with an invalid return address? Or
simply silently disregard them?
This is already defined in the standards. DSNs are not sent if there is
an empty "MAIL FROM" address, so "reject" would be equivlent to "discard"
in this case.
* using this action in response to a UCE/SPAM message will almost NEVER
be useful, and in most cases will make the problem/impact worse
Agreed. But Sieve is designed for much more than just
UCE/UBE/SPAM/whatever. See my previous message for why a "bounce/reject"
action provides vital functionality.
- Chris