Thanks for this help. I just switched from qmail to postix on Plesk 9.5.4 and I had the same problem with port 587 so I added 587 inet n - - - - smtpd -o smtpd_proxy_filter=127.0.0.1:10025 -o smtpd_client_restrictions= to the master.cf file and it started working, but email could not be sent...