AMaViS and ClamAV

When configuring AMaViS to use ClamAV internally, you should not forget to add the ClamAV user to the AMaViS Unix group:

   sudo adduser clamav amavis

Otherwise you'll be seeing the following message in the log file:

   451 4.5.0 Error in processing, id=24139-01, virus_scan FAILED: virus_scan: ALL VIRUS SCANNERS FAILED: