Can you? It's arguably much more annoying than other providers because you can't use a normal email interface. I've been trying to switch off it for a while and just use a normal provider with simplelogin slapped in front. Also, the spam filter isn't very good.
You can do this with any email. What's your point? The reason for the rise of email providers advertising encrypted email is because PGP is a pain for most people to use and never saw widespread adaption among regular users.
you cant because tutanota has no POP/SMTP/IMAP so its basically just a web form. you could of course add PGP to any such communication medium but it wont be very standard
Presto