MS vs. Amavis

[Chris Trudeau]

> -amavis development is fragmented into various forks of the project.

Amavisd-new is the most stable of the three general forks mentioned above,
while fragemented, amavisd is extremely well supported by the communitiy
which includes several notable names.

>  Along with that comes fragmentation of the user/support community.

While I somewhat agree, the support has been stellar from all included in
Amavisd-new mailings.

> -amavis doesn't do spam filtering

Neither does MS.  They both leverage outside support of SA which with all
external plugins is extremely accurate and configurable.

> -amavis AFAIK calls an instance of your virus scanner for every single
>  message whereas MS gathers mail up into batches and invokes the virus
>  scanner for each batch.

This is not entirely accurate.  Amavisd-new does support several of the
virus scanner which can run in daemon mode including clam and sophos to
mention a few.  While MS does a batched process, that could argueably NOT be
better as there COULD be performance related issues with batched jobs no
matter how long the timeout is between "checks" of the disk...although it
DOES appear to handle failures by MailScanner processes well as mail can
stillbe received, just not delivered. (depending on your MTA)

> -MS focuses on scanning mail. amavis tries to do smtp. it seems better
>  to leave that to the MTA

Seems a bit paritsan of an answer, the daemon that handles the listening for
mail is really small, slick and conforms with the applicable RFCs relative
to writing to disk and handling of messages...(from what I can tell)

>
> Just a few reasons we're looking at switching. I'm sure others will have
> more.

I am actually using both currently in test.  MS is handling initial receipt
of messages, hands them off to an amavisd-new implementation.  SA scores are
alomst identical and the accuracy is great.  I have had some problems with
MS dying on me though and have not had to restart amavisd yet...HOWEVER...

The configurable nature of MS with rules based processing is STELLAR.  I can
easily say that my need to support several domains with completely different
requirements is achieved with MailScanner hands down.  I would rather
seperate SA prefs for each domain...but that is antoher topic altogether.  I
like them both, but because of the rules-based config, I will probably go
with MailScanner.

I STRONGLY recommend trying both and determining which REALLY meets your
needs...they both have great strong qualities.

CT