More and more exciting reviews about Tutanota are popping up online: "Given that Tutanota is open source, and they have a pipeline of amazing products in development, I pulled the trigger and moved my email there." 😁 We're always happy to hear what our users think, let us know so we can add your review here:
https://tutanota.com/blog/posts/tutanota-secure-email-review
Tutanota email reviews - updated.

Tutanota is one of the most secure email services due to its focus on encryption and open source. Check out these reviews.

@Tutanota I moved to Tutanota along with both my domains last week and it's been working great so far. Really like it, you did a good job setting up a user-friendly encrypted mail service.
@quad Thanks for your feedback, that's good to hear! 
@Tutanota
I feel very strange every time you say "Tutanota is open source" because my brain immediately adds "only on the client side". Are you doing that on purpose?
@datione Of course, it's the client-side - which handles the entire encryption - we never said anything else. Though we plan to build a small open sourced server (not as complex as the one we are using) that people will be able to host locally. But this is a lot of work, and a bit further down the development road. Thanks for your patience!