Symantec Security Gateway vs. Custom Linux Box?
michaelr asks: "I run several email-based discussion lists. While only members of the lists are allowed to post, I've lately had problems with viruses as they often impersonate the members (or the members themselves are infected). I've identified two solutions: either build a Linux box running SMTP-based antivirus software, or purchase something like the Symantec Gateway Security which includes AV among lots of other things. The street price makes it a little more expensive that a Linux box + AV software, but it seems to be zero maintenance. The problem: the Symantec device is new, and before I place my trust in it, I'd like to know: has anyone had any experience with it, or should I just build the equivalent myself?"
Personally I prefer to do things myself, but you can't do everything all time. So the real question is, if this box comes with support (and what quality that support has), rather the question if you can trust it now. Just like your home made solution, it will have bugs and will need patches/upgrades etc. If you have a channel to report problems to, and they fix it for a resonable subscription price, then go for it. You should also ask, for how long the support will be available (1 year, 10 years, ...).
I have had success setting up OpenBSD with Postfix and RAV.
OpenBSD - Free operating system, similar to Linux if that's your primary exposure to UNIX-like environments. OpenBSD doesn't have all the bells and whistles of Linux, but on the flip side it doesn't have the baggage either. It is very well suited to setting up a secure server. The built in firewalling, IMHO, is one of the things that sets OpenBSD apart from all the others. It's a snap to firewall an OpenBSD server and there are plenty of example configs out there to get you started.
Postfix - Sorry, Sendmail just gives me fits. I don't want to have to have a reference in front of me while configuring my MTA. I know enough about SMTP to make intelligent decisions if my options are put in front of me in English. Postfix does this. Not to mention it is free, it is fast, it is secure and it is a drop-in replacement for Sendmail.
RAV - This is not free software, but it works very well with all of the software named above. RAV is an antivirus program that is called by Postfix. It's very fast, and very effective.
Since you're running a mailing list server, you might want to do some creative de-miming to further increase the effectiveness of your efforts. Other than GPG signatures, most MIME is unwanted anyway.
At one of my last jobs I used this setup:
Linux + Sendmail + Amavis + Sophos
Once I had it setup I could completely forget about it. Setting up the Amavis with sendmail was a trick, but I had a homebrew sendmail.cf file because of some complications with our mail setup. Once that was done, I signed up for sophos email alerts. From that mail I setup a script to be run when ever one of those mails came through to go out to sophos' website and get the update.
All in all, we never got an email virus coming into our network after that through this box.
Norris/Palin 2012
Fact: We deserve leaders who can kick your ass and field dress your carcass.
The Symantec firewall formerly was known as "Raptor Firewall" or "Axent Raptor Firewall". It is a hybrid firerwall with quite a number of transparent security proxies, whereas Linux machines "only" do stateful plus maybe (standard) proxies for only a limited number of protocols. For a class overview see http://wyae.de/secure_gateway/gateways.php
In my experience the Raptor is(was) quite good and not really comparable to a custom linux machine or off-the-shelf linux firewall (e.g. Astaro) - though I like the latter, too. It's playing in a completely different (IMHO higher) class.
The Raptor's SPs are among most stringent I know of - but can be a real pain to pass through for nearly-compatible stuff. The Notes SMTP gate was infamous for being rejected by Raptor because of RFC-noncompliance...
Apropos "maintenance-free": no forewall is maintenance-free. Never. You'll always have to have a look at the logs, at unusual behavious, etc. The only difference here is wether you have to care about building software patches yourself or to have a company do that for you. But the load of necessary maintenance work still is to be done. If you ignore that, you'll pay the price, probably earlier than later...