I might be biased, but I self-host both XMPP and email, and XMPP is easier. Roughly equivalent in resource usage for a small private server. Snikket (a project

I might be biased, but I self-host both XMPP and email, and XMPP is easier. Roughly equivalent in resource usage for a small private server. Snikket (a project I started) is probably the easiest way to get a modern XMPP setup these days, or (if you're more into system packages than docker) it's pretty straightforward to get up and running with Prosody, this guide being a good indication of the few things to think about beyond "apt install prosody".