If you are on Android, K-9 Mail is wonderful[0]. But you need to host your emails/calendar/contacts somewhere, for that, I am very happy with Fastmail[1]. [0]:

If you are on Android, K-9 Mail is wonderful[0]. But you need to host your emails/calendar/contacts somewhere, for that, I am very happy with Fastmail[1]. [0]: https://k9mail.app https://k9mail.app [1]: https://www.fastmail.com https://www.fastmail.com Edited to add that K-9 is an email client (app), but not hosting the emails.