Ability to view draft revision history
When collaborating with teammates on email drafts, a revision history would allow for worry-free collaboration, keeping drafts of emails from accidentally being deleted. Auto saving drafts every few seconds when composing an email then being able to recall past iterations in the event of a draft deletion would be fantastic.
I agree and the addition of an 'Undo' button to recall the previous draft should a deletion or modification be performed in error would be really helpful.