The barbershop quartet recording that became the first email attachment
Early email was strictly limited to plain ASCII text—sharing images, sounds, or formatted documents was impossible. In 1992, computer scientist Nathaniel Borenstein co-authored MIME (Multipurpose Internet Mail Extensions) to allow email to carry any media type. To prove the protocol worked, Borenstein emailed a message to colleagues containing a photo of his barbershop quartet, The Telephone Chords, along with an audio file of them singing a barbershop jingle about sending email attachments.
The 7-Bit Ceiling of Early Email
In the earliest decades of computer networking, sending an electronic message was fundamentally an exercise in transmitting plain text. The foundational standard for network mail, formalized under RFC 822, established conventions for addressing, delivery headers, and basic message bodies. However, this system was conceived within the strict technical constraints of the era, which assumed that communications would consist almost exclusively of American English text. The entire mail architecture was engineered to handle seven-bit US-ASCII characters, creating an environment where any data outside the standard 128 character codes simply had no native way to pass through.
This seven-bit ceiling meant that early email systems were incapable of handling binary data directly. If a user wished to send a digitized image, an audio file, or a compiled program, the underlying mail transport software would corrupt or reject the transmission because binary data uses the full eight bits of each byte and contains control codes that early mail servers misinterpreted as instructions or end-of-file markers. Even human languages that required accented characters, non-Latin scripts, or custom typographical marks could not be natively expressed, forcing international correspondents into clumsy phonetic spellings or non-standard encodings.
While computer enthusiasts and engineers developed interim workarounds, such as manual hex dumping or running files through standalone conversion utilities like uuencode, these fixes required tedious manual intervention. The sender had to encode a binary file into printable characters, paste it into the body of an email, and hope that the recipient owned compatible software to cut the text out and reverse the process. There was no automated mechanism within the mail protocol itself to declare what a file was, how it should be converted back into its original form, or how a computer should present it to a human user.