Symptoms
-
The following warning is received while creating a mailbox in Plesk:
Warning: Unable to apply the Mail Anti-Virus settings because you have reached the maximum number of mailboxes defined by your Premium antivirus license key.
Cause
A non-licensed version of the Premium Anti-Virus for Servers extension is installed on the server.
Resolution
If the extension is planned to be used further, consider purchasing a license.
If the extension is not planned to be used further, remove the Premium Anti-Virus for Servers extension.