Q: further idea (No need to publish this) - the following is pure gold if you think about it.
Would a API access be possible? If so, did you ever thought about the abillity for people running communities (Insta, FB, Circle, Tribe, YT, Heartbeat, Discord...) woudl love the idea about their community members getting an email for "community internal" comms - secured?
Briefly:
1. Add API or at least, email creation by incoming webhook and send back the confirmation to the originator or simply team with Heartbeat and community platforms alike.
2. User signs up with the community but the community creates a free email account based on the users chosen namespace
3. community internal newsletter and alike are sent encrypted within the community using your system
4. users learn they now got a free and secure email that is getting more and more secure the more people are using it.
5. If user leaves community there must be an option to keep/delete namespace and block it for 36 month or so to avoid abuse.