Found a solution.
On SPAM Settings, blacklist @
At the witelist put the emails allowed.
In my case I put @domains.ext, email@example.com
Latest posts made by arymaynart
Lock Knowledgebase to loged in users only
How to allow Knowledgebase access for loged users only?
The thread bellow disable it permanently. This is not what i want. I need to keep it enabled but only for users that are logged in.