Everyone has the need for an anonymous email account i.e. an email account that can not be traced back to your real world identity.
These email accounts work great when they are the only information required to successfully create an online account. They don’t really work so well if you are required to also provide a name and you use your real world name (doh!).
Unfortunately Tutanota don’t accept payments via cryptocurrencies e.g. Bitcoin, so you can’t pay them anonymously. This isn’t a show stopper because as I’ve previously mentioned they do provide free accounts.
Tutanota is open source (GNU General Public License v3.0) so if you are so inclined you can read through the source code.