Walking through MIME fields: Snubbing Steve Jobs to Star Trek tech
Email daddy Borenstein talks rejection and attachments
What next for MIME? The world wild web awaits
The timing was ripe for MIME, coming on the heels of CERN-based computer scientist Tim Berners-Lee's work on the first world wide web server, web browser and humanity's first web site in 1991. Berners-Lee needed a way to exchange multimedia messages but didn't want to re-invent the wheel.
"Just as we reached this consensus on the MIME standard, Tim Berners-Lee and his folks said they had to figure out how to do multimedia, so they said 'let's use this new MIME thing'... this thing I'd never heard of called the World Wide Web adopted it and took over the world," Borenstein said.
Fate played its hand several times in the making of MIME, and therefore the internet as we know it.
First, there was Borenstein's interest in email that stemmed from his service job at CMU - all students were assigned tasks outside of their studies. His job was running CMU's email system in 1980. "That turned into my entire career, which wasn't my goal at the time," he told us.
Borenstein joined the Andrew Project upon completion of his thesis, and it was Andrew that inspired MIME. Andrew tagged files with a content header but it used just a flat namespace that assigned everything a single label; this meant the list of possible headers became cluttered and content didn't always come through as readable. You might open what you thought was an image only to be confronted by pages of densely packed random characters - the raw data of the picture.
It was through Andrew that Borenstein met email pioneer Einar Stefferud, active in internet standards and credited with inventing the first internet mailing list, at a conference where X.400 - rival to SMTP email - had dominated discussions.
Stefferud was impressed by Borenstein and hooked him up with the person who was to become his MIME collaborator, Ned Freed. Borenstein's interest was in the exchange of multimedia content while Freed's interest lay in building a gateway between different email systems. By the time MIME went to the Internet Engineering Taskforce (IETF) for discussion, people had piled onto MIME's third aspect - sending non-English without it becoming gibberish.
"I was the only person with a paper not on X.400. I ran into these people who believed email can't do what I've already made it do [with Andrew]," Borenstein said of the X.400-heavy event. "Einar made a beeline for me."
Getting MIME accepted internationally at the IETF was a matter of politics. The landscape was a battlefield of the kinds of technology disagreements, vendor bickering and a hazy belief that market forces would pick a de-facto standard that we would come to know and, er, love. Often, Borenstein says, the best way to get critics onside was to conceded a minor point and then add them to MIME's lengthy list of contributors. Just one person rejected this play, he said, an individual who believed MIME was "very ugly".
A better built MIME
To this date, Borenstein concedes MIME could have been built better but accounts for its design on the need to be backwards compatible with huge chunks of what is now regarded as the internet's backbone, ARPANET, that was already in place thanks to the military and universities that pioneered it. Back then MIME had to support FTP and data encoding used on older servers as well as Base64 and ASCII. "If you were starting from scratch, you wouldn't start at Base64 and 7-bit ASCII," Borenstein says.
Two decades on, and despite its complexity, MIME is embedded in the internet. Borenstein, who is chief scientist at Mimecast, reckons one trillion MIME attachments are exchanged every day. The number of MIME types to describe different media has grown considerably from the original 16. Its success is because of the freedom you have in being able to define new name types.