[Dovecot] Dovecot and Bogofilter

Matthias Andree matthias.andree at gmx.de
Tue Nov 11 00:13:32 EET 2008

On Mon, 10 Nov 2008, Matthias-Christian Ott wrote:

> > it's not quite clear to me how this would work with bogofilter as a
> > mailbox_transport - bogofilter isn't designed to do final delivery.
> > 
> > It's also not quite clear to me why people would use procmail. Although
> > defended by its maintainers, it's an unusable and unconfigurable piece
> > of software from ancient past -- getting error handling right in
> > procmail is next to impossible, requires forfeiting :e rules and
> > bloating procmailrc with explicit error handling recipes.
> If you haven't puked today, just look at their source code and programming
> style. I think the configuration and exit code handling is not the worst
> problem in this software.

I know that I don't want to read that code. It looks like something in
between a "dirty C tricks to squeeze the final cycle from compilers that
predate even peephole optimization" and a submission to obfuscated C
contest. User interface? Fallthrough behaviour on delivery errors?
Nevermind how randomly mail is spread across your mailboxen :-)

> > If you want something and Dovecot's deliver doesn't fit your needs,
> > consider maildrop, <http://www.courier-mta.org/maildrop/>
> Looks a bit bloated to me.

Nevermind the bloated build, it works like a charm and has a rather
concise source (if you read a bit of C++, that is).

> > Bogofilter has an "integrating-with-postfix" document in the doc/
> > directory that shows how to use Postfix's content_filter and does not
> > need procmail. Unfortunately, it does not show how to integrate updates;
> > there are several approaches to achieve that. One way is to use separate
> > mailboxes where users can send mail to and where they are picked up by
> > cron - best when using Dovecot is probably to make users move spam into
> > particular folders via IMAP.
> I read that document some days ago, but the content_filter approach
> looks strange to me, because they use sendmail to reinject the E-Mail
> in the queue.

Well, I co-authored that document, but it's just a refined version of
the "Simple Content Filter" as per Postfix's FILTER_README... check

Postfix's content_filter=... setting diverts the mail from regular
routing, and the sendmail command (without -t!) reinjects with original
headers and recipients (from envelope) for then regular routing.

Looks scary to some, but works.

BTDT, although I've moved on to amavisd-new since. Saves the hassle of
training spamfilters with virucide fodder...

Matthias Andree

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