Undo Send facts

While investigating facts about Undo Send, I found out little known, but curios details like:

Gmail's "Undo Send" option was originally a bug that was turned into a feature

Gmail has an ‘undo’ setting that allows you to delete erroneous emails for up to 30 seconds after sending

In my opinion, it is useful to put together a list of the most interesting details from trusted sources that I've come across. Here are 2 of the best facts about Undo Send I managed to collect.