Can restoring from a backup allow me to reaccess a email account I accidentally deleted?

How do I recover deleted email account from iphone? I accidentally deleted it. The email account was a billion years old and I can't remember the password. I have been locked out of this email account and cannot get back into it. If I were to backup my iphone to itunes and then restore a backup from before I accidentally deleted it would that deleted account be accessible from the old backup? Then in the future I can restore from a current backup from today. Please help I'm so frustrated.