Can I ask why you didn't just use email? If you wanted a technical challenge you could have setup your own email server. You could also run your own Teamspeak server for video conferencing.
This is the problem with matrix et al. They have to offer something that is leagues ahead of the current baseline, which I'm not convinced they are.
We aren't using email for this, because we wanted a chat room. We aren't using Teamspeak because we don't want video conferencing.
I've been running my own email server for going on 20 years now.
[edit] To add to the above, I use the same Matrix server to chat in various Matrix, IRC and Gitter rooms, and also to host a couple of self-written bots which I use to control a few aspects of my life. Email isn't really a replacement for the things I use Matrix for.
This is the problem with matrix et al. They have to offer something that is leagues ahead of the current baseline, which I'm not convinced they are.