Ability to lock emailsto prevent accidental deletion,

Blaine Gaither

In administrating ones email account it is too easy to accidentally delete an email and then not notice that you have deleted an important one.. Especially if you have selected a range or page of deletions.
The requested feature would allow a user to lock or unlock an individual or group of emails. A locked email cannot be deleted. If you attempt to delete a locked email you get a warning message that states that you must unlock to delete. No fancy permissions or categories are needed. . Just enough to stop you from deleting an email that you have marked as locked, will prevent most accidents.