postfix alternatives on NetBSD / pkgsrc

[Mayuresh <mayuresh%acm.org@localhost>]

Short story:

A quick search shows exim as the main alternative. I am looking for
efficiency and if possible clearer semantics (than postfix!) of the
configuration files.

Please do suggest alternatives.

Long story:

There is a separate mail thread in which I am sharing my experience of
setting up a mailing list (on an experimental basis right now). I'd prefer
using an MTA first for this, the list being mostly static. Would go to MLM
software only if I fail to get it right with MTA.

I think I have got nearly everything right with postfix (my current and
default MTA), except that when I `reject' an email sent by a non member to
the list, the sending servers (such as gmail) report that my mail server
is not configured properly.

The status code returned is (554 5.7.1) actually fine, but I am not sure
whether there is indeed any issue with my configuration that draw this
remark. Bouncing of an email for protecting senders to an id should not be
such an unusual scenario for the sending server.

Further I am not sure whether to just ignore the error that senders would
get. This is because there is some probability of sending server
blacklisting the domain on recurrence of such bounce.

So thought of giving an alternative server a try to see if for a similar
situation sending servers complain or not.

Mayuresh