Why will my iPad not let me sign in with my email address to use iMessage and FaceTime?

Every time I sign in with my Apple ID it will ask me what email address I want to use to receive FaceTime calls and iMessages on, so I put in the same one I use for for my Apple ID and it will say 'verifying' for quite a bit of time before it tells me that it will send a verification email that I never get, or it will go back to the log in part where I have to log in again, it never works, help.