All I know is that after I’ve configured my mail server from within WebMin, if I do not change the smtp to smtpd, my emails are always stuck in the queue. Until I edit it to the smtpd option and then restart postfix I can not send, but can receive emails; my outgoing queue keeps getting bigger and bigger. Perhaps it’s something else that I have set incorrectly, but it works the way I’m doing it so “if it ain’t broke, don’t fix it”, if you know what I mean 