Comment by isaachinman

Personally, I use iCloud+ for custom domain hosting. I migrated from Gmail about a year ago. Yes, it's a walled garden, but a lesser of two evils for sure.

And if you have email accounts spread across multiple providers, check out the email client I am currently building:

https://marcoapp.io

Supports anything that supports IMAP/SMTP, but crucially is cross-platform (desktop + mobile apps).