When they reply that they have deleted the account, do you assume that they also delete any information that they have stored or that they simply close it and keep the information?
Personally i want them to delete my email name and other information so that it is not at all in their systems.
The problem here is, that I can’t write and check, without them creating a new account for that email
Sounds like you’re using a less than optimal app to browse lemmy. Have a look around for one of the hundreds of post about app recommendations