David wrote:
> Hi,
>
> I've got a small Postfix/Spamassassin/Procmail system which is
> configured to bounces all mail that isn't for a valid local user
> (default setup I believe). The "problem" is that it's also bouncing
> stuff that is obviously spam but I'm puzzled as to how (or the best way)
> to stop this, whilst still bouncing real emails (we have several users
> who's names are often mis-spelt and so we do want genuine customers to
> know if their mail hasn't been delivered).
>
> The way I've configured my setup, Postfix doesn't do any spam testing
> and instead I've wholly used Spamassassin for both RBL as well as Bayes,
> et al, testing for spam by using a Procmail recipe to pipe the mail
> through Spamassassin. Invalid local users are being rejected by Postfix
> before getting to my Procmail recipe in any case.
>
> I'm a bit reluctant to simply enable RBL checks in Postfix as it's a
> simple pass or fail. I like Spamassassin's scoring so that periodically
> anything marked as spam is (humanly) checked and any false positives are
> dealt with. To make Spamassassin scoring as accurate as possible I'd
> also still want to keep the RBL checks in Spamassassin, so I'm doing RBL
> lookups twice for each message.
>
> Is it therefore best practice to create a catch-all local user for
> Postfix to deliver "invalid user mail" to and then modify the Procmail
> recipe so that after piping through Spamassassin I bin anything
> identified as spam for this catch-all address and send a preformatted
> "bounce" email to anything identified as ham?
>
> I tried Googling for a suggested solution but only came across enabling
> RBL checks in Postfix.
>
> Anyone any thoughts?
>
> Thanks, David

You can stop Postfix from rejecting unknown local recipient addresses with:

local_recipient_maps =

Then, you can tell Postfix to send all email addresses to unknown recipients
to a single local UNIX account of your choosing, with the "luser_relay" configuration setting.

See: man 5 postconf

--
Greg