

I also use Posteo, one thing to note though is that Posteo doesn’t (and probably won’t any time soon) support custom domains. If that doesn’t bother you, it’s a great choice.
The other alternative I found during my research, which doesn’t have that limitation, is mailbox.org.
I was pretty neutral towards Ubuntu, up until an automatic system update removed my deb Firefox and replaced it with the snap version, even though I specifically set the apt repo to a higher priority.
The entire reason I left Windows is because I don’t want (for example) Edge shoved down my throat after every update, and yet Ubuntu has gone and done the exact same thing with snaps.
After literal hours of fighting, the only solution I found was to fully disable automatic updates. With Pop OS I have all the benefits of Ubuntu, but I also get a company (System76) that does cool stuff and doesn’t try shoving snaps down my throat.