Hi people
Is there any way i can control spam like:

Dont let somebody@somedomain.com sent us email , or force somebody@somedomain.com allways can send us email?
I mean, how can I control somebody@somedomain.com can send us or no sending us email manually?

Sometimes we have peoples mail marked as spam and we need to receive this message, and sometimes we detect some spemmers account and want to mark it as spam manually.

Thanx