TIL: IP address is a legit part of email address!
You can (theoretically) send a message e.g. to user@1.1.1.1 (and maybe even @1.1?)

Imagine also IPv6 was a real thing and we could send messages directly to any device. P2P email... I wonder if that could work out :blobcatthinkOwO:

For boring details, see serviceobjects.com/blog/ip-add