Thanks for this! I did not even know about Purelymail, and have been considering moving to a new mail provider. Protonmail, Zoho, and Fastmail are all on the list of options. I'll add Purelymail.
I tried all of them except of Protonmail, which doesn't support IMAP. Fastmail is fine, Zoho is really cluttered and Purelymail is my current favorite.