I really enjoy F-Secure's Antivirus for Exchange product.  It just silently, quietly cleans up junk from mailboxes. It's nice to have it pick up unusual phishing scams.  I've never had any headaches with F-Secure.  It's fast, efficient, and doesn't create any noticeable load on the server.  The distributed scanning ability makes it something I'd definitely recommend.  Updates happen very often too!

Contrast this with Symantec or McAfee for Exchange - both of which just give the server a very bloated feeling. Strange crashes, slow access times... F-Secure has yet to cause me a single headache.  It's properly implemented, and just feels clean and tight.  Functions completely transparently without the need of constant intervention.

I've implemented and deployed at least 5 installations of this product for clients.  I'm sold.  I would never use another product on my Exchange boxes.

Use F-Secure Antivirus on your Exchange boxes.  Nothing else.

Product Page
http://www.f-secure.com/products/anti-virus/fsavme/
http://www.f-secure.com/products/anti-virus/fspame/

2005-06-02  13:20:23-04:00  SERVER  SERVER\Administrator  F-Secure Anti-Virus for Microsoft Exchange
 Malicious code found in:
  Source: CharterOne online banking
  Destination: Username
  Subject: Information for CharterOne bank customers.Read Inside.
  Folder: /MBX/USERNAME/Inbox
  File name: text/plain
  File size: 1239 bytes
  Scan result: Trojan-Spy.HTML.Bankfraud.hl
  Action: Dropped
  Quarantined filename: infect\FSAVMSE200506021320237121