I’m about to fire up Mail-in-a-Box on a server and have a few questions before getting started.
 I initially started up a clean Ubuntu 20.04 LTS server to use for Mail-in-a-Box, seeing as that’s the most recent LTS release. However, when I ran the setup script for Mail-in-a-Box, I discovered that I needed to be running either Ubuntu 14.04 (odd…since that’s been deprecated for 3 years unless you have an ESM subscription), or 18.04 (again, only 1 more year of support without ESM). I figured 20.04 would be safely supported since 22.04 must be right around the corner. But apparently not.
Is my best bet to hold off on building a Mail-in-a-Box mail server until 22.04 is released and supported by Mail-in-a-Box? Or should I go with 18.04 for now and start building right away?
Will Mail-in-a-Box be supported on Ubuntu 22.04 fairly soon after 22.04 is released?
If I do go with 18.04, does the Mail-in-a-Box upgrade scripts ever include distribution upgrades as well, to make this truly an “appliance” type application? Say for example, going from Mail-in-a-Box version 50 to 51 also upgrades Ubuntu from 18.04 to 22.04 as part of the process.
 Mail-in-a-Box seems to be a fairly zero-touch application as far as actual changes to the server via SSH are concerned. Therefore, how safe is it to be connecting to a Mail-in-a-Box server and running, say, apt-get update / apt-get dist-upgrade or apt-get upgrade? If one of the packages that gets upgraded is, for example, Postfix, Dovecot, or nginx, is this the end of the world for Mail-in-a-Box and I should only be performing updates to the server by running the upgrade script to newer versions of Mail-in-a-Box? Or is it perfectly safe for me to be performing regular server updates in between Mail-in-a-Box releases?