I’ll confirm everything everyone else said. Hosting your own email server is a major pain in the ass for many unrelated reasons. The mail stack is complex. You need to do a whole bunch of things right to avoid your setup from getting flagged as spam. You need to secure it real well. Hosting it at home is likely to be almost impossible because it is very common for residential internet subscriptions to have the required ports blocked, and the ISPs will very often refuse to open them for you even if you have a nice static IP. Getting around that is not gonna be easy.

There’s a reason why so many ardent homelabbers refuse to touch email hosting with a 10 foot pole.