Yes, you must be on the device (i.e. computer or tablet) on which you originally created the email and it must be within the last 5 hours of creating the email.
Log back into your account.
Go to the Message Library and select Create a New Email Message.
* VERY IMPORTANT - Allow the email builder to populate the last unsaved email *
If you have templates to choose from you must choose the same template or you will lose your work.
Tip: Tired of scrolling? You can expand and collapse the email header information by clicking on the top right hand side of the email body. This will bring the email body up to the top and make it easier to edit.