I gave up self-hosting ages ago. For a while I even used the old Google for Families grandfathred in setup. That also went the way of the dodo a few years ago for me.

I signed up for ImprovMX, setup my domains there, and just route my emails to whatever service I want. I use a random gmail account that I use for my login and Google services, but the email itself is never exposed anywhere, I only give out the custom domain one.

ImproveMX handles routing for my whole family. My mom uses Outlook, and it routes there for her. If google, microsoft, or whatever give me trouble or ban me, I just quickly switch the email and nothing lost.

If you pay for their service, since they have a super generous free tier, you also get SMTP servers to use as outbound, which lets me send emails through them and not have the `on behalf of` email thing. Also they do all the work to make sure their IPs aren't blocked and in good standing with MS, Google, etc.