[Dovecot] Dovecot aspects of fighting spam

[Frank Cusack]

> I hadn't gotten to reading much about Sieve, yet, as what I had read
> said it was something IMAP users would run.

Man oh man.  You don't have much experience with mail and it sounds
like you are starting from scratch.  You have your work cut out for
you. :)

The standard way to filter spam is [all of]:

a) stop it at the border, then
b) content analysis and tagging, then
c) filtering at delivery time

per-user filters for part (b) on the server side is a dead end IMHO but
there are some programs that do this and dovecot can work with them
(by having folders that train the filter).  modern mail clients, however,
have their own spam filters now, which are by definition personalized.

anyway, part (a) and (b) have nothing to do with dovecot.  the standard
way to do part (c) is to have an X-Spam: header which a sieve script
filters on.  the -m flag to deliver is not really for spam filtering.

-frank