InvalidUserName in asp.net CreateUser when creating a user with . character before the @ character

Question

I looked up the msdn documentation and it says that InvalidUserName is thrown when it does not find the username in the database, which is fine because the user I am creating should not exist in the database.

If I use [email protected], it works, but if I try it with [email protected], the status from Membership.CreateUser is InvalidUserName.

Answer 1

Email addresses come in the form username@domain where domain is at least two parts separated by a period/dot.

The RFC Specification says that a . in the username part of the address (the part before @) is valid unless the . is the first or last character (of the username), so the behaviour that you are noticing is correct.

http://tools.ietf.org/html/rfc5322

Good find @David Stratton: From the wikipedia link in his comment...

Character . (dot, period, full stop) provided that it is not the first or last character, and provided also that it does not appear two or more times consecutively (e.g. [email protected]).