Allow customisation of filenames of drag-and-dropped messages

If a message is dragged from a message list and dropped into a folder open in Windows explorer, the resulting file is named with the subject of the message and a .eml extension. It would be helpful if the format of the file name could be customised.  In particular, it would be helpful to be able to include the date and time of the message as part of the file name so that multiple messages from a conversation can be dropped into the same folder with unique names and with an alphanumeric sort order that places them in chronological order.
So instead of a dropped file being called “subject.eml” it could be called something like “2018-07-17_10h43_subject.eml” or anything else that a user wants.

That happens already if you drag more than one message, but it would be extremely useful if it would also happen with a single message.

Great idea. You have my vote.