Block domain or email addr. in postfix

In /usr/local/etc/postfix/access_sender, add email or domain which you want to block.

debelan88@gmail.com reject_unverified_sender

To reject and send explanation message, that mail server wont accept the mail, you must use reject_unverified_sender not REJECT. REJECT rejecting the mail without explanation message.

after add desirable domain or address, you need to update access sender database:

postmap hash:access_sender

– YOU MUST BE IN THE DIRECTORY WHERE IS ACCESS SENDER FILE

If you don`t have in main.cf strings about error messages you must add them on hand.

unknown_local_recipient_reject_code = 550

unknown_client_reject_code = 550

unknown_address_reject_code = 550

unknown_hostname_reject_code = 550

unverified_sender_reject_code = 550

unverified_recipient_reject_code = 550