Guest Order Problem: Customer Service Agent or customer submits order in Magento as guest and accidentally passes the order through with an incorrect email address. Customer doesn’t receive their order confirmation email because of this and inquires to CS to send it to correct email. CS cannot modify their email address on the order and can only resend the order confirmation email to the original email address entered for that order. Challenge: Give CS ability to modify customer/guest email on the order level so that they can resend order confirmation email to new email.
Solution : I just built mobule which help CS to Update Email address for Guest Orders.
Please download all files and follow same structure to copy files in your magento.