In the pre-smtp days, email links were over UUCP, which was often relayed via dial up lines which connected intermittently, on a schedule (e.g. every hour). You also specified not just the destination, but also the route for the email to take, via a 'bang path': https://en.wikipedia.org/wiki/UUCP#Bang_path Add in the situation of disk quotas for university students, but not email quotas, and you get the means, motive…
Since the statute of limitations has expired I will admit to creating data archival systems using uucp as well as smtp. Back in the 80s before the morris worm and spam, when the internet was just for us geeks, you could usually connect to anyone's mail server on port 25 and hand it mail to be delivered just about anywhere. Sendmail was more concerned with connecting up all of the various networks than it was about au…
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