Latest main.cf changes

[rbtux]

the sender_restrictions has nothing to do with especially sending e-mails... the sender_restrictions restrict mails using information available after the mail from: command while recipient_restictions restrict mails based on information available after rhe rcpt: command

so within recipient restriction you can do all restrictions necessary. This is important when you add some black/whitelists. When you permit something within sender_restrictions you can't block that in the recipient_restrictions...