Spam filters make it problematic to self host email because sent emails will likely get marked as spam by the reciever. It is on my list to try and get a basic one working localy or hosted off site to get around the restrictions.
What do I do about email?
Proton Mail is a good alternative to big tech and has a free option with limitations but it is usable. The paid plan is affordable and comes with lots of lovely features like a VPN. We could also do a family paid plan which would be cheaper and provide a good off site files backup option.
You can also keep using your current email as you work through the transition away from big tech.