Praveen had a comment on our final draft:
"I'm not sure if we should recommend tutanota. For self hosting there are many options like mail in a box, iredmail or setting up each components manually.
For end to end encryption, the only 100% guaranteed way is to do it in the client. So we should focus on pgp for encryption, it is a well established and widely supported standard, where as tutanota is using their own, which has not tested enough.
To make pgp easy, we have new apps and standards like pep and autocrypt which makes end to end encryption transparent and easy to use. All a user needs to do is use an app that supports these standards and key generation and sharing is handled transparently."