Postfix – Blacklist – Absenderadresse sperren

# vi /etc/postfix/sender_access

user@domain.dom REJECT

# vi /etc/postfix/main.cf

smtpd_recipient_restrictions = check_sender_access hash:/etc/postfix/sender_access

# postmap hash:/etc/postfix/sender_access
# /etc/init.d/postfix reload