Yes,
I have been playing with the Sophos a bit. It seems to work fine and I think it uses the Mcafee data base wich you can setup to automatically download with cron. They do not yet provide the automatic checking of inbound e-mail right out of the box. At least not the last time I checked. But I was able to find a shareware version of inflex that put a front end on sendmail that checked mail. It was done via scripting.
Hope that helps too,
Troy