mail server recommendations?

[Mark Johnston]

"Michael W. Lucas" <mwlucas at blackhelicopters.org> wrote:
> I'm looking for a decent solution for a mail server software package.
> We need SASL, IMAP, pop3ssl, antivirus, and mime-type filtering.  In
> an ideal world, we'd have the ability to create mail accounts without
> creating user accounts.

On a fairly small (15-domain) personal box, I'm running postfix with a 
PostgreSQL backend.  The postfix smtpd_recipient_restrictions, 
virtual_mailbox_maps, virtual_mailbox_domains, and virtual_alias_maps are all 
stored in the DB.  The POP3/IMAP is provided by courier-imap, which supports 
SSL, pulling the logins and maildirs from the same database table that 
Postfix stores them in.  For me, mail accounts without user accounts was a 
requirement, and this scheme provides that nicely.  What I wound up with was 
a users table that looks like this:

id           |   crypt   |   home   |   maildir              |   uid   |   gid
mark at xl0.org   CRyptedpw       /      var/vmail/xl0.org/mark     525       525

The UID and GID are the same for all users, since there's no access to those 
directories other than by the mail servers.  The home and maildir look that 
way to make postfix and courier play well together.  I imagine MD5 passwords 
could be used, but I migrated this from a legacy system that used crypt.

I realize this doesn't match your requirements exactly, since it doesn't use 
SASL (no relaying done at all), but the support is there in postfix.

I haven't set up antivirus and mime-type filtering, but I did look at them 
once, and it seemed straightforward - there are plenty of packages out there 
that support postfix.

> I have to admit that I'm partial to sendmail simply for the milter
> interface that lets me plug in, say, MIMEDefang, clamav, and all sorts
> of other nifty stuff.

I didn't consider sendmail for this project, mainly because I'd used postfix 
before and liked it.  The postfix interface for plugging in virus scanners 
and the like strikes me as rather clunky, though - it's just a bunch of SMTP 
daemons chained together.

I haven't included a whole lot of detail, since I did this mostly by tutorial 
- googling on postfix courier brings up the ones I used, mostly with MySQL, 
but it's interchangeable with Pg from a Postfix perspective.

Mark