Premium Antivirus is the default mail antivirus program shipped with Plesk. If an additional license key for Premium Antivirus is not added to the Plesk license key, only 14 mail accounts are protected.
Plesk allows to enable spam protection for any mail account, but only for the first 14 mail accounts. This is the limitation of the free version of Premium Antivirus.
To protect all mail accounts, order a Premium Antivirus license.
For more details about what accounts will be secured, refer to:
- 213409149 How does free Premium Antivirus define which 14 accounts to secure?