I use Mcafee Groupshield for Exchange!
Along with it's ability to Scan incoming/outgoing Emails -
It can Block Attachments by - Size, Extenssions, FileNames Etc.

(I block EXE, com, VBS, BAT, CMD, JS, MPG - To Save up Bandwidth...)

Another Neat thing is that you have Outbreak Manager - who can Detect "Virus Like" beahviour on the Exchange Server!


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It Works Better if you Plug it in, It Works far better if you Turn it ON!