hi, Whats the 'robust' way to make sure email to a specific destination is only accepted if it came over the localhost:25 or /usr/sbin/sendmail route ? anything else should get a 5xx error. Emails to other destinations should remain unaffected. Using postfix/c4. Had a look around, and header_checks might be one way to go. -- Karanbir Singh : http://www.karan.org/ : 2522219 at icq