Two bits of information would have helped me as I onboarded to the Proton ecosystem if they were placed front and center:

1. Make it obvious that there's a limit to the number of times you can delete an email. As I set up a strategy for myself, I created a number of emails that I then wanted to rename, and hit the limit of deletions. This could be as simple as showing a generic message every time a user tries to delete an email that says "Are you sure you want to delete this email? You are only allowed to delete an email X times.

2. Although I'm fairly technical, I'm new to the world of self-hosted email DNS. I first set up self-hosting through Proton Mail, and then found that one can also self-host email domains through Proton Password to use for aliasing. It would have been very helpful in both places to say that you can not host the same domain for each use case - it needs to be one or the other. Many people probably know this, I did not, and it would have saved me and Proton Support time by surfacing this info up front.