The `/var/lib/amavis/virusmails` directory functions as a quarantine area for email messages identified as containing malicious content by the Amavis content filter. When Amavis detects a virus or other threat in an email, it moves the suspect message to this directory, preventing it from reaching the intended recipient. The administrator can then examine the quarantined messages for false positives or analyze the threats. As an example, if an email contains a file identified as a Trojan horse by ClamAV (the antivirus engine Amavis often uses), that email would be stored in `/var/lib/amavis/virusmails`.
Regularly managing the contents of this quarantine directory is important for several reasons. Primarily, it helps maintain disk space on the server. Unchecked growth of this directory can lead to storage exhaustion, impacting system performance and potentially causing service disruptions. Furthermore, reviewing the quarantined items provides valuable insights into the types of threats targeting the system, aiding in the refinement of security policies and filter configurations. Historically, failure to manage this directory has been a common source of server performance issues in email environments using Amavis.
