by Darius Kazemi, July 15 2019

In 2019 I'm reading one RFC a day in chronological order starting from the very first one. More on this project here. There is a table of contents for all my RFC posts.

Mail box

RFC-196 is titled “A Mail Box Protocol”. It's authored by Richard W. Watson of SRI-ARC and dated July 20, 1971.

The technical content

Let's get it out of the way: this is not the invention of the modern protocol for email. It's a proposal for something that acts a hell of a lot like email, though.

This “Mail Box Protocol” is a way for a Host computer to have a file that gets continously appended with the content of inbound files sent to a “mail box”. Each file sent to the mailbox has a unique identifier to denote its boundary, so you could use a program to browse one sub-file after another. If these were text files, you would in fact have something that looks a lot like email.

This is being proposed because the NIC would like to send documents and messages to remote sites, and to receive them as well, “without having to know the details of path name conventions and file system commands at each site”.

In Watson's words,

A mail box, as we see it, is simply a sequential file to which
messages and documents are appended, separated by an appropriate
site dependent code.

The Mail Box protocol uses the Network Control Program, the Initial Connection Protocol, and the Data Transfer Protocol. So they are not reinventing the wheel here. Files are to be 7-bit ASCII, which to me implies that they really want this for the transmission of text documents like RFCs, rather than more complex data types.

The idea is that incoming messages can be held on disk storage for later printing, or simply read on a screen. But it's kind of amazing that they do suggest having a printer set up to just automatically print out all incoming mail!

They recommend that all messages sent to the NIC (which would be given mail box number 0) contain a header with the sender's name and address (presumably postal address?), and the receiver's name and address “formatted in some reasonable, easy-to-read form for a clerk to read and distribute”.

The author also recommends that socket number 5 be reserved for incoming Mail Box connections.

How to follow this blog

You can subscribe to this blog's RSS feed or if you're on a federated ActivityPub social network like Mastodon or Pleroma you can search for the user “@365-rfcs@write.as” and follow it there.

About me

I'm Darius Kazemi. I'm an independent technologist and artist. I do a lot of work on the decentralized web with ActivityPub, including a Node.js reference implementation, an RSS-to-ActivityPub converter, and a fork of Mastodon, called Hometown. You can support my work via my Patreon.