[Wietse]
I just stubled across this thread:
http://www.gossamer-threads.com/lists/exim/users/90005
We could take a bold step and do it in two "main stream" MTAs,
damn the torpedoes.
Let's not call it a bold step, let's call it a bottom-up approach ;-). I
can't speak for Oracle, but I wouldn't be surprised when Oracle would
implement it in Sun/Oracle messaging server as well. If it would be
implemented in Postfix and in the Oracle mail server, there would be 5
MTA's with (experimental) code/plans for this functionality (MeTA1,
Exim, Sendmail are the others).
[Viktor]
Is it worth the effort? Will enough SMTP clients whose messages
What is 'enough'? It's one of those chicken and egg problems that can
only be solved by starting somewhere and see what happens. This
discussion keeps popping up, the draft is (I believe) dated 2007, in
2010 there was a discussion on the ietf-smtp list about post-DATA
responses, Wietse referred to an Exim user list thread of January 2011
and now in November 2011 we're discussing it again.
Another typical use case is described by Ned Freed in
http://www.imc.org/ietf-smtp/mail-archive/msg06122.html: user-level
sieve filters. And even if the use of this extension would be of little
value in a WAN context, it might solve problems in a LAN context.
[Claus]
I don't know -- I implemented it because I like the feature
and I was a bit involved in the discussion on the PRDR draft.
one may be inclined to partly reject actually support this extension?
Well, the MTAs that support it will hopefully do it both as client
and as server.
+1
If not, what do we gain by only being able to apply per-recipient
content-dependent policy to a small fraction of the traffic from
largely legitimate MTAs?
The current way some filters implement per RCPT filtering is done
by applying the filter to the first RCPT and every RCPT that doesn't
have the same filtering configured will be temp-failed, hence there
is extra load (queueing, retrying) on the client to send those RCPTs
again. This could be considered an incentive to implement the feature
on the client side.
When would Postfix reply negatively for recipient "A" and positively
for recipient "B" after DOT? How would this be exposed to existing
Per RCPT filtering is a feature that is often asked by ISPs who
offer anti-spam/virus for their customers: some pay for additional
filtering.
Altough I'm not an ISP this is exactly the reason I was trying to setup
per-recipient filtering and sent my question to the list.
/rolf
