/etc/postfix/master.cf
submission inet n - n - - smtpd
-o syslog_name=postfix/submission
-o smtpd_recipient_restrictions=$mua_recipient_restrictions
smtps inet n - n - - smtpd
-o syslog_name=postfix/smtps
-o smtpd_recipient_restrictions=$mua_recipient_restrictions
/etc/postfix/main.cf
mua_recipient_restrictions = check_recipient_access hash:/etc/postfix/blacklist
/etc/postfix/blacklist
user1@example.com REJECT
user2@example.com REJECT
После внесения изменений выполняем:
postmap /etc/postfix/blacklist
postfix reload