An alias can enable mail service, despite being disabled on a subscription level

[mahesh]

Question
An alias can enable mail service, despite being disabled on a subscription level on a Plesk server
Symptoms
An alias can enable mail service, despite being disabled on a subscription level.
Cause
Recognized as bug PPPM-14467.

Resolution
The issue will be fixed on one of the next Plesk updates.
There is no workaround currently.