All start to work after adding these two lines in `master.cf` in postfix: smtp unix - - n - - smtp -v -v smtp inet n - n - - smtpd -v -v postfix/smtpd - This is typically the SMTP daemon process for handling incoming mail and routing to the appropriate internal location. postfix/smtp - This is typically the SMTP daemon process for delivering mail out to the world. smtp inet n - n - - smtpd this line tell postfix to send mail via 25 port