I have a Postfix server I have setup and I want to limit access to it as follows: Scripts running on the server are allowed to sendmail without auth. Virtual Users can connect via SMTPAUTH from anywhere in the world. SMTP connections are only allowed from a series of predefined IPs and users mentioned above. No other SMTP connections are allowed on the server. Is this done by specifying the IPs in mynetworks and then running something like: postconf -e 'smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject'