I've been a pretty happy dreamhost customer, because they offer flat-rate email bundled with their shared hosting. However, they:

* do not have API administration

* do not have a catch-all feature

* require that you have another email address on file [**]

* provide service only when you buy a hosting plan for $$$/year

[**] At dreamhost, they require that I have a non-dreamhost account to which they can send recovery codes. This means I can be hacked if someone compromises dreamhost OR if someone compromises proton mail.