Twenty years ago, researcher Nathaniel Borenstein emailed a picture and recording of his barbershop quartet, the Telephone Chords (he's pictured at far right above.) The two files were the first-ever attachments that could cross the boundaries of specific email systems, making them a viable form of communication. Today, about a trillion Multipurpose Internet Mail Extensions (MIME) attachments are sent each day, based on a standard that Borenstein and partner Ned Freed invented, and The Guardian has caught up with Borenstein to discuss his revolutionary system.

Despite its importance today, the attachment was seen as niche or downright frivolous in 1992. Borenstein remembers that during his time at phone giant Bellcore, "people found it inconceivable that rather than posting a film photograph in the mail, you would prefer to scan and transmit them over a slow modem." After saying that when he had grandchildren, he'd want to email pictures of them, "people laughed." Borenstein has clearly gotten the last laugh here, but even he still has complaints about the attachment system — starting with the name. Instead of an "attached" file, he initially wanted pictures or sound to be included in the body of the email. Even more frustrating to him is the fact that each attachment contains 19 bytes of redundant code. It's a tiny number compared to the size of attachments, but Borenstein says that it still adds up to 7 wasted petabytes a year.

He also scoffs at the "death of email." Mailing lists or bulk messages could be replaced by social media, but he still sees the system as the best way to communicate person-to-person. And the mass of information that's currently sent over email provides it with a tremendous advantage. "Email, which some people say is dying, continues to grow," Borenstein says. "And most dying things don’t really do that."