[NCLUG] MTA

[Bob Proulx]

Hi Steve,

Steve Wolf wrote:
> So far I've been able to ignore my server's MTA configuration, but the
> company I'm using to email my RSS feed has gone belly-up and I want to
> convert to a mailer on my server.
> 
> Should I choose sendmail, postfix, or exim?  Why?  Please, no
> religious wars here. :-)

What everyone else said (good stuff, couldn't have done better) plus:

Sendmail is a single large monolithic program that runs as root.  That
gives it a large attack surface area to defend against.  If you can
crack it then you are in as root.  Postfix by contrast runs smaller
dedicated programs as a non-root user trapped in a chroot.

Sendmail uses a Turing-complete rewrite rule language that is in some
ways similar to sed.  I like sed.  But I find working with the
sendmail rewrite chains to be like reworking someone else's assembly
language programs.  They can easily be write-only code.

Postfix operates mostly by decision tables.  Almost any particular
decision to be made during the handling of an email message is made by
the contents of a decision table.  The tables are quite straight
forward.  For example if you want to route mail differently based upon
destination then in Postfix a transport table would list a destination
on the left hand side and the way to get there on the right hand side.
That is a relatively simple but powerful paradigm that is easy to
understand and maintain.

Exim seems to perform just fine and is certainly a contender.  I would
find it hard to criticize since a lot of people use it and like it.
But on systems that I access that run exim I just find it strange.  In
a subjective and hard to quantify way.

I use and recommend Postfix.

Bob