Hello,
> you could use clamav and have virus protection for all your users for
> free.
unfortunately this is not a solution for the problem I described.
1. Please don't start a discussion about ClamAV, but ClamAV doesn't do
its job very well, because the virus signatures always lag behind
signatures of the big players (like Symantec or Kaspersky) and ClamAV is
really worse at heuristic which should catch all the mutations. I could
give you links to proof that ClamAV has not passed several tests to
detect very new virus, but thats not the point.
2. It doesn't matter which virus scanner we are using. Each user
(mailbox owner) must be able to disable the virus scan, otherwise it
would infringe German law.