Spam Fighting in Exchange
By Simon Bisson & Mary Branscombe in Editorial
How can you fight spam with one of the most common email servers out there? After all, surely that should mean it’s an easy play for the spammers, with enough holes to get every V1agr4 advert and pump-and-dump scam into your users’ mailboxes.
It turns out it isn’t - and that the built-in tools are effective spam blockers.
If you’re not using Exchange 2007 Content Filter (or Exchange 2007’s Intelligent Message Filter) turn them on. This is one of the most effective weapons in your arsenal. It’s regularly updated, and it scans messages for common spam formats. Mesages are categorised and given spam ratings, which you can use to reject, quarantine, or file messages in users’ Junk Mail folders. CF is surprisingly easy to use - set it up, set the basic filtering rules, and then occasionaly check your quarantine mail box for false positives.
Exchange 2007 has even added whitelisting for persistently filtered false positives. Once a domain is whitelisted, there’s no more delving in the spam folders for Twitter invites or press releases from Kaspersky and Sophos.
I’d been running my server like that for some time, when I discovered another trick that turned out to make a huge difference. Exchange actually supports using real-time block lists (RBLs), which are lists of spam IP addresses hosted by services like SpamCop and Spamhaus. It’s trivially easy to add new block lists to Exchange - just find the lookup address on the block list site (Spamhaus’ is zen.spamhaus.org), and add it and the provider name in the Block List Provider section of Exchange’s anti-spam tools.
Without RBL support turned on I was getting 500 or so spam messages in my quarantine a day, making it hard to filter out the few false positives. With it on, I’m down to less than 100. Managing my spam is a lot easier - and with whitelisting, I’m having to look in the spam folder a lot less often…
–Simon
Not yet rated
Loading ...
Tag cloud
Archives
- September 2009
- August 2009
- July 2009
- June 2009
- May 2009
- April 2009
- March 2009
- February 2009
- January 2009
- December 2008
- November 2008
- October 2008
- September 2008
- August 2008
- July 2008
- June 2008
- May 2008
- April 2008
- March 2008
- February 2008
- January 2008
- December 2007
- November 2007
- October 2007
- September 2007
- August 2007
- July 2007
- June 2007
- May 2007
- April 2007
- March 2007
- February 2007
- January 2007
- December 2006
- November 2006
- October 2006
- September 2006
Most commented posts
- Java's SSVAGENT.EXE: training the monkey
128 comments
- When Windows 7 upgrades won’t hibernate (the solution)
- Do you need IPv6 for DirectAccess? Yes and No
- Chrome OS: what happens when "always connected", isn't?
- The ColdFusion Renaissance
- Make Adobe Acrobat Pro deactivate
- Is there a showstopper bug in Windows 7 CHKDSK?
- There’s a reason smartphones are locked down
- At sixes and Windows 7s
- The LHC isn
Highest Rated Blog Posts
- Songs of distant satellites (100%)
- Nobody knows what Web 2.0 really is (100%)
- Log in and lock in (100%)
- Top tips for speeding up Vista (100%)
- Mommy, why is there a home server in the office? (100%)
- Employees are our most valuable asset (snigger) (100%)
- Locking down IT or blocking creativity (100%)
- Consumer BlackBerrys are good for business (100%)
- HD Trek (100%)
- Join the (beta) community (100%)
