Returned emails are "read only", they cannot be edited and resent. There is an easy way to convert a SENT email to an UNSENT one, so you can rework it just like new. Did you know that just a single line inside the email tells Outlook whether it has already been sent or not? If you add "X-Unsent: 1" to the correct place in a sent email it will revert to an unsent one. Magically revert SENT to UNSENT emails with these Handy Outlook Tools.