This is 100% a design flaw.  I would call it a bug.   Not a fix; are you aware of email plus codes?  After the username part, you can put a + and another bit of text, and it will still go to your email address.  For example, these will all get delivered to the same place: user+phone1@comapny.com user+phone2@comapny.com   My horrible solution, sign up as a second administrator using a plus code email address, ... View more