Gmail was one of the first (if not, the first) email applications to thread messages of the same subject into a single conversation. As I was playing around with this feature, I noticed a minor discrepancy between what happens when you delete a single message versus when you delete an entire conversation. It turns out that after deleting an entire conversation, Gmail gives you the ability to Undo (or undelete). However, the same is not true for deletion of individual messages. Let’s take a look.