The USPTO granted a truckload of stupid patents in the early days of the Web. One of the stupidest was the Tumbleweed patent on 'using SSL encryption designed to secure Web communications to secure mail messages delivered through a Web site'.
When email was first invented, messages were small and storage was expensive. Even people considered heavy Internet users at the time might receive only a few dozen messages a week. When I looked through my own mail files from the period to look for evidence for a patent lawsuit, I was astonished to find how few emails I sent and received. Mail messages tended to be small as well. Because mail attachments were only invented in the early 1990s and many mail clients didn't support them until the turn of the millennium.
One consequence of this situation was that at the time few people saw a problem with the SMTP email architecture in which the sender of the message pushes the whole message out to the receiver. Most email users were familiar with the Internet FTP protocol and they considered email and data distribution to be two completely separate and independent things. The idea that someone might want to email a movie to another user simply did not occur to most. Making the suggestion was to invite derision.
Today the need for this type of capability is met by companies such as Dropbox that do a very good business providing what is in essence an email system in which the data sits on the mail server of the sender until the receiver asks for it.
This sounds like exactly the sort of capability that should have been added to the Internet email standards but that wasn't possible because the USPTO had issued Patent 6,1924,407 which is in effect a patent on the idea of push email.