It's bad out there when it comes to hosting your own email server. This blog post shows somebody's experience in detail, and it's worth reading. https://cfenollosa.com/blog/after-self-hosting-my-email-for-twenty-three-years-i-have-thrown-in-the-towel-the-oligopoly-has-won.html
It's all so sad.
Every community should own their own communication infrastructure, or they don't actually own the community. It can disappear in a second. Matrix, Rocket.Chat, Mattermost, IRC, whatever. An online community relies on the connecting tissue, so if you care about your community you need to own it.
Pleroma, Owncast, Nextcloud, an internet radio station, and a couple web sites.
Gabe from #Owncast here happy to answer any questions about independent live streaming. While it sounds like out of grasp for most people, it's actually quite easy and low cost to run your own live stream. I've seen many people say they run Owncast on a $5 VPS, or even off their home internet connection using things like the object storage feature of Owncast.
If you'd like to see some use cases detailed there's a document here that goes deep into the numbers to show how for many livestreaming scenarios it's shockingly approachable. https://owncast.online/docs/resources-requirements/