Hello, Please can help, how can I set postfix to send email just with valid email account, and if the email adress not have a email account to send a error message. Thanks in advance.
Try adding this to /etc/postfix/main.cf: Code: smtpd_reject_unlisted_recipient = yes smtpd_reject_unlisted_sender = yes Also you might try the 'Reject sender and login mismatch' setting in Server > Server Config > {server} > Mail (see http://www.postfix.org/postconf.5.html#reject_sender_login_mismatch and note ISPConfig actually uses reject_unauthenticated_sender_login_mismatch, just below that).
