How to setup a Mail Relay in Postfix?
How to setup a SMTP Mail Relay in Postfix?
Follow the guide below to configure Postfix to use outMail as a Internet Mail Relay.
This article already assumes your Postfix system is able to send emails externally and that you are already have a terminal connection to your server with the necessary access rights to manage and administor postfix.
where OUTMAILUSERNAME and OUTMAILPASSWORD are the (case-sensitive) information provided when you set up your account.