I've seen a lot of commenters on HN like Fastmail and have nothing but praise for it.

But I disagree with

> all come with a modest price tag

The price tag may be modest for some people, but is not for everyone. If someone needs one mailbox per person in a family, the costs go up a lot with Fastmail. There are cheaper alternatives that have been around for long (though probably not doing things like developing new protocols such as JMAP). Some of these alternatives may also be suitable for people who don't want email to be hosted in the US.