Install Postfix and its dependencies using the command sudo apt install postfix. During installation, you'll be prompted for basic configurations like the mail server type, system mail name, and ...

Excellent that should do it.<BR><BR>Any downsides to not telling Postfix it's a backup MX and just altering the priority in DNS so that it's the primary for the outage period?

I can send an email and then it will show up an hour later. It seems that eventually the SMTP server that Postfix is trying to connect to takes the queued mail.

HowtoForge – This document describes how to install a Postfix mail server that is based on virtual users and domains, i.e. users and domains that are in a MySQL database.

Unpack the source tarball as follows: $ tar –xzf postfix-2.0.6.tar.gz Create a postfix user account, with the primary group named postfix, using your account creation tool of choice.

Resources for “Adding Clam Antivirus to Your Postfix Server” Linux Journal by Mick Bauer on December 1, 2004 ...

Postfix will now reject mail with a “Relay Access Denied” message, no longer revealing whether a user account exists. You can use an asterisk in the access map as a wild card to block ranges ...