I can't imessage my other iphone4 it says not delivered and ask me to try again and gives me the option to send as a text

Question

OK so I have two new 4S phones with the new imessage feature, one phone is mine and the other phone is my wife's. I have one itunes account that recognizes both phones as the same email account in the Apple ID in the imessage settings on both phones. We are having problems with the imessage working between us. When we are sitting next to each other it works, but when we are at our seperate places of employment and text each other we get imessage error's "Not delivered", it works fine as a regular text, so I'm  guessing it has something to do with both phones having the same Apple ID. How do I get her phone to have her own seperate Apple ID, or is there another way to resolve this issue? Neither one of us has unlimited texting so the imessag feature is really great for us if it will work.

Answer 1

Try simply dismissing the popup by hitting cancel and then Get Mail from the account in question.
See also
http://applehelpwriter.com/2012/01/17/mail-wont-remember-passwords/