While creating an email account, make sure to apply these requirements to the account’s name:
Account name’s length
Your username can be 1-50 characters long. Your username can be any combination of letters, numbers, or symbols.
Usernames can contain letters (a-z), numbers (0-9), and periods (.).
Usernames cannot contain an ampersand (&), equals sign (=), underscore (_), apostrophe ('), dash (-), plus sign (+), comma (,), brackets (<,>), or more than one period in a row (..).
Usernames can begin or end with non-alphanumeric characters except periods (.).