Thank your for the reply. While I am not too familiar (yet) with the Policy Daemons, it seems somewhat straight forward. What I do not understand in your suggestion is the multiple smtp_bind_address statements. It's not clear to me how that will effect delivery to separate smarthosts or relay hosts. We forward ALL mail to a relayhost owned by us, but via two different (one public and one private) routes.
I do not wish to have multiple default routes to the outside, rather, I am only trying to force smtpd to deliver either via the relay host A or relay host B based on email size. I understand that I can force all non-local mail to deliver via relayhost=[a.some.domain] and alternatively smtp_fallback_relay=[b.some.domain]. I guess I'm still trying to determine whether I can force mail by size restriction via one relayhost or another. If this is done with the smtp_bind_address I guess I have much more reading to do. Hopefully that made sense. Regards, -David > From: Wietse Venema <wie...@porcupine.org> > Reply-To: Postfix users <postfix-users@postfix.org> > Date: Mon, 25 Jan 2010 14:57:32 -0500 (EST) > To: Postfix users <postfix-users@postfix.org> > Subject: Re: Cost based routing > > DAVID HASSILEV: >> >> Hello, I have tried to search through the list archives but have not found >> what I'm looking for so I thought I'd post to the list. > > To implement routing policies depending on message size, > > - Implement a Postfix policy daemon to examine the message size > attribute (invoked from smtpd_end_of_data_restrictions). > See: > http://www.postfix.org/SMTPD_POLICY_README.html > http://www.postfix.org/postconf.5.html#smtpd_end_of_data_restrictions > http://www.postfix.org/postconf.5.html#check_policy_service > > - Have the policy daemon respond with "FILTER A:" or "FILTER B:" > or "dunno". A and B are the names of smtp client entries in > master.cf, each with their own "-o smtp_bind_address=xxx" option. > See: > http://www.postfix.org/master.5.html (for "-o name=value) > http://www.postfix.org/postconf.5.html#smtp_bind_address > > This requires Postfix 2.7 snapshot 20100117 (or later). To make > this work you will also have to tweak the network stack to support > two "default" routes to the outside world. I can tell you only the > Postfix side. > > Wietse >
