For this overload:
if CreateUser("username@email.com","pwd") , failed with error message :The e-mail address provided is invalid. Please check the value and try again.
but CreateUser("username@email.com","pwd","username@email.com") , succeed!
why?
It may be better to think of the methods like this:
Without reflecting the code I couldn’t say 100% for sure, but I’ll bet those functions just call an internal function that takes in every possible parameter.
So your first call (simplified) is actually:
If you have configured your provider to require email address, then clearly
nullis not valid.From the MSDN docs: