Thanks for the fast answers.
I will revoke the post and reply attribute from the registered-users group and create a new group with post and reply permission, where I add users based on some rules.
Problem is solved 🙂
I want to prevent spam posts with disabling post setting. Only "Global Moderators" and "administrator" can post topics.
How do I change the setting?
Just select a category you want to apply this restriction to (if you want it to work globally, you can select any category and just copy its settings to all) and remove "create topics" privilege from everyone but Global Moderators.
@oplik0 Thank you!