Comment by evgen

Back in the day, when protocols were more trusting we would play games by storing data archives in other people's SMTP queues. Open the connection and send a message to yourself by bouncing it through a remote server, but wait to accept the returning email message until you wanted the data back. As long as you pulled it back in before it times out on that queue and looped it back out to the remote SMTP queue you could store several hundred MB (which was a lot of data at the time) in uuencoded chunks spread out across the NSFNet.