depend on what you need. Mail is a protocol where if you dont selfhost, the provider can do what he want with your identity and your data. You can encrypt all mails, but still a lot of metadata is leaked (also, if you use mails for common services means you cant encrypt all mails and your data is leaked to provider on daily basis).
So the best way is compartimentalize your identities, use different mails for different needs, and selfhost if you really need something more in terms of privacy. 
Frankly all services are pretty the same, I use protonmail as a kycname@mail.com, I dont expect any privacy from them. For pseudonimous mails cock.li is a good provider, he is very open and clear with what he can do.
Hopefully nostr will make mail obsolete.