Best I can figure, choose a company that has well established general hosting services and get email through them.

It's going ro be really interesting to see if Thunderbird is able to make a good alternative. I really like the direction they are going, but time will tell if is sustainable for them and users alike.

Personally, I'm using Hostinger, which is reasonable and reliable.

Some people are relying on specialty private email providers like Proton or Tuta, but I have a big dose of skepticism. Lots of people are canceling their Proton subscriptions, and Tuta depends on using their clients because of the secure way it's built.

I would not be interested in attempting to self-host email. The service itself is trivial for an experienced network person (which I'm not), but the big picture is impossibly complex. There is a complicated and somewhat opaque reputation system that will arbitrarily block a lot of self-hosted email services. Some people have found ways to make it work, but it always seems pretty tenuous to me.

As far as email archiving, I highly recommend self-hosted Bichon, which I have run for a while and love it. I keep a few months of email locally, and the rest is on my server backup. It's straightforward to setup and use, fast searches, easy automations, etc.

As others have said, radicale is excellent for hosting calendar and contacts through CalDAV and CardDAV. I've used it exclusively for a while and never had an issue. The formats are pretty standard, so you more or less get your choice of client on any system.