Fighting spam with Exchange 2007

Spam sucks. We all know that. There is no better way of putting it — especially if your company has ever been hit with 10,000 pieces of spam in a single day. It’s not too far-fetched a scenario: According to Jupiter Research, the average e-mail account received 2,200 spam messages last year, and all that spam costs the nation’s businesses some $9 billion per year, says Ferris Research.

Ye there are plenty of excellent spam filtering solutions on the market these days. In fact, directly within your Exchange 2007 server infrastructure, you can establish free anti-spam agents (yet another reason to pursue Exchange 2007 for your environment).

[ How did Exchange 2007 fare in testing by InfoWorld Test Center? To find out, read “Microsoft Exchange 2007 pushes the envelope.” ]

For a really great step-by-step tutorial through the anti-spam features, see the Exchange_Genie blog.

This may cause you to wonder: If I have nine agents working for me, why would I need anything else? The answer: The nine agents use a variety of proven methods to block most spam types — but spammers are resourceful little monkeys and they’ve evolved their techniques over time.

For example, while blocking software focused its attention on keywords like “viagra,” spammers started using “v1agra” instead. And when blocking software used blocklists of IP addresses (which we have in Exchange 2007), spammers simply change their spam origination IPs more often. Spam filtering in 2006 moved toward Bayesian filtering — and spammers countered with image-based spam (images with text that, of course, couldn’t be scanned yet).

The latest spam techniques that are proving quite effective is the use of PDF attachments (which are now being blocked through scanning), then Excel attachments, and then Excel attachments zipped up. It’s a back-and-forth game between spammers and admins, and you can see how you may need more than one solution in your environment.

That’s not to say Microsoft isn’t keeping up with anti-spam features though and you can read about these here. Actually there are updates to the definitions of the anti-spam agents provided through the Windows Update process. As important as these are… depending on the CAL options for your server, you may or may not get first rate service. For example. If you have an E2K7 Standard CAL… you will only get anti-spam definition updates for you content filter every two weeks! Whereas the Enterprise CAL (with ForeFront) updates your server once per day! In addition, Enterprise CAL get spam signature updates (several times a day) and IP reputation updates (several times a day). So, there are updates to the anti-spam agents. But if you didn’t go in for the Enterprise flavor of Exchange you may not be getting all them, according to the MS Exchange Team.

The site TopTenReviews offers a 2008 review of software spam filters that you can investigate. The top three? SpamEater Pro, CA Anti-Spam, and ChoiceMail One.

On the hardware side, the spam filter appliances come in different shapes and sizes, two of my favorite appliances being the Barracuda Spam Firewall and the Sunbelt Ninja Blade.

On the free side there is Spamato, SpamBayes, SpamPal, K9, and a host of others; check out a rundown of 14 of the best anti-spam tools for the personal user.

So what kind of spam filtering are you working with? Do you love it or hate it? Please provide the feedback that only you can!