I keep getting this error message when I try to create a new account at https://account.nabucasa.com/signup/ using a .com e-mail address that works everywhere else and has been valid for nearly 30 years.
"Mailbox does not exist."
Why does your system have such a basic bug?!
The domain name is my username on here, followed by .com, and the user part of the address is my first name on here.