Are you buying domains for fun? you can setup email easily
mailway.app
mailway.app
I would recommend maybe changing that, but I understand if you want to keep it.
I have also used ImprovMX and had good success there, although I ended up leaving because the free plan was too limiting and the paid plan was too much ($10/month last I checked).
Both services have great UX. It's hard to go wrong. I'll probably try out Mailway as well just for comparison.
Note I'm not affiliated in any way with forwardemail or ImprovMX, just a happy user.
I've heard that Gmail actually has a pretty good API, but I haven't looked into it. Has anyone tried using gmail from the API?
mailway will provide webhooks when an email is received, no plans to actually send emails yet but mailgun has a good API.
From a security perspective, the emails will be readable from such a service.
I haven't tried it myself but the maintainer is prominent in open source so I'd be pretty optimistic.
Totally fine if you don't know, but I may hold off investing time into something else if you expect it to be soon-ish.