For what reason are you trying to avoid docker? since most projects provide docker images and an example docker-compose.yml it’s very easy to get the application you want running.

Otger projects that do plug and play application setup like yunohost etc. are casaOS and umbrel (both use docker under the hood btw)

If you use let’s encrypt certificates on that subdomain it’s pretty easy to find. https://crt.sh/

the family computer running ubuntu from 2010 on. I used it mainly for Web browsing and creating presentations for School. I was able to run League of Legends (that was in 2014 i think) through wine but i think it crashed in about 50% of Games during the loading screen :D. Linux gaming has truly come far since then (and now LoL doesn’t run on Linux at all because of Riots Rootkit)

Why do you want everyone to execute her?

The best about homepage is configuring it via docker labels

I use Ubuntu server as well and for me it mainly was that I was already familiar with the Ubuntu way of doing things. :D And Ubuntu Server has a few more convenience features like kernel livepatching. And I think the software on Ubuntu LTS is a bit less outdated than that on Debian stable

I run Anonaddy on a oracle cloud server without issues. You’ll need some SMTP relay service like smtp2go or mailjet of course. But other than that it works fine.

Port 25 is only blocked outbound. Recieving mail works fine on oracle cloud free tier servers.

I use docker-mailserver which is just one docker container running the basic services without the complexity of a webui an managing groupware