

Thanks :)
Email is just the communication channel. The relevant code for sending the activation code is just a few lines. Though, there is of course more work to be done for full integration:
- validation of the matrix ID in the frontend (probably a regex?)
- storing encryption keys and room IDs for conversations in order to continue sending messages in to the same encrypted room with users
- adding a mechanism to select either email or matrix for users and allowing secondary matrix IDs (should the user want that)
It should be possible to have this in more projects, but it would probably take a big player to recognise a value (encrypted communication with their users) and adopt it.
simplelogin provides email aliases? Using a matrix ID doesn’t solve spam issues. The service could be hacked and all matrix IDs leaked and it would be the same as your email address being leaked.
So, an equivalent service or feature would have to be created for matrix that allows users to generate aliases for use with different services.
rambling of other (non) solution
Ooor, users could sign up with room IDs! That would actually solve the problem. As user could create a private room, copy the ID into the signup form, and the service would send messages into the room. It could save the list of participants in the room, i.e your matrix ID though 🤔 So not really a solution.
Good question! Thank you for asking. This would indeed require a solution and aliases built into a matrix server would be the best option. Maybe… uh… @JadedBlueEyes@programming.dev as a matrix server developer could think of something?