Some of you may already know about this but for those who don’t or forgot. After setting up your mail server you should run a mail relay test. This will run several tests against your MTA and verify it’s properly configured. By default Zimbra ships postfix such that it’s not a relay. However any custom config may open your server up for abuse. Always better to check before a spammer finds you!
Please to disable the mail relay setup?
How to disable the mail relay setup?
How do i test my zimbra configuration for an open relay?
Is my mail server open relay?
I need to know if our e-mail server is open relay over Internet.
Tank You