Uses for Older Mac Mini

I have a late 2012 Intel i5 based Mac Mini, that is running Catalina (10.15.7), but won't update any further due to age. I'm planning to upgrade my "daily driver" to a newer machine, but this one still works fine. I'm just starting to get a lot of apps complaining that they soon won't be supporting Catalina any longer (and as we all know, a newer machine will be nice too.) But it makes no sense to "toss" this one, which is still, for all intents and purposes, still good. I do graphic design work, so some of the ideas I've had would be to use the i5 as:

eMail Server

Web Server

NAS/Storage "server" (?)

It has 16gb of RAM, and a 2TB SSD, so it's got enough horsepower to handle any of these tasks. (My Raspberry Pi's do more with less, so I see no reason the Mini wouldn't handle such tasks easily.) I haven't done any hunting as yet, for eMail or Web Server software that will run on Catalina, so I'm looking for ideas what to do here.

Thanks in advance.