We strongly recommend that virus scanners exclude the VPOP3\pgsql\data folder and all subfolders. If a virus scanner decides to quarantine a file from within this folder structure, that can cause VPOP3 not to run, and could lead to data loss or corruption.
We also recommend that backup software does not backup this folder structure. If a backup program opens a file for backup, and then the database server needs it, it can cause problems, and crashes.