So unfortunately, I've been tasked with setting up an Ubuntu server to send and receive email (amongst other things). My friend is hosting the Ubuntu VM on his box, but has only done limited setup ...

If you do this, be sure your SMTP server isn't set up to believe any <I>local</I> SMTP traffic is valid, or the spambox could just send everything through your Exchange server.

How to configure SMTP for Bitwarden Before you attempt to create a new account on the server, you’ll need to configure SMTP settings, otherwise, you cannot confirm your new account.