Reminder that you can go for hybrid approaches; receive email and host IMAP/webmail yourself, and send emails through someone like AWS. I am not saying you can't do SMTP yourself, but if you want to just dip your toes, it's an option.

You get many of the advantages; you control your email addresses, you store all of the email and control backups, etc.

...

And another thing: you could also play with https://chatmail.at/relays ; which is pretty cool. I had read about Delta Chat, but decided to play with it recently and... it's blown my mind.