re: [Exim] virusscanning for incoming mail

    http://duncanthrax.net/exiscan/
It only scans each message once. It requires that you run exim in queue-
only mode. It then scans each message in the queue, and when done with 
each message, tells exim to deliver it. I use it with McAfees uvscan. Exiscan 
was developed expressly for use with EXIM.