The half written emails in Mail app on iPhone or iPad saved as drafts, which a user can access later. Apple includes a faster way to access saved message drafts on iPhone and iPad in new iOS. So, continue reading to know the method to open email drafts list of all of your email accounts on iPhone and iPad.
Access Saved Draft eMails on iPhone and iPad
Step-1
Tap on Mail app icon from the Springboard of your iDevice
Step-2
Tap and hold Compose button, which appears in the lower right corner of Mail app screen

Step-3
A combined list of saved draft emails from all of your email accounts will get open. Tap on a draft email, you want to continue, complete it and simply send it

See also:
How to Delete Messages in iOS 7