Email delivery protocols / methods.

Peter Coghlan cctalk at
Fri Jul 5 17:06:50 CDT 2019

Grant Taylor wrote:
> Here's pot stirrer for a holiday Friday afternoon:

It's not a holiday in most of the world, including where I am, however...

> How many different protocols / methods can we collectively come up with 
> for how email can be transferred?
> I'm primarily thinking about between servers (MTA-to-MTA).  But I'm also 
> willing to accept servers and clients (MTA-to-MUA).  Where you can / 
> could run at least one server yourself.
>   · SMTP(S)
>   · UUCP (rmail)
>   · MMDF
>   · X.400
>   · Microsoft Exchange proprietary protocol
>   · Novell GroupWise proprietary protocol
>   · Lotus (IBM) Domino proprietary protocol
>   · FidoNet (FTN)
>   · BITNET

BITNET isn't really a protocol.  Perhaps you mean NJE which was the protocol
used to implement the BITNET and related networks?  Although I think BSMTP
(batch SMTP) was usually used to transfer mail over NJE networks.
(Speaking of which, anyone want to join an NJE network?)

>  · Direct file access - group Post Office

I'm not sure what this one is.  Does it refer to POP/POP2/POP3?

>  · Direct file access - mail spool

I have no idea what this one is. "Mail spool" could mean mean all sorts of
different things on all sorts of different systems.

Another one was the coloured book protocol used between academic
establishments over X.25 networks in the UK and Ireland and probably
elsewhere, Grey maybe, I forget which, probably for the best.

Then there is DECnet and/or Mail-11 depending on what level of protocol you
are talking about.  And phonenet which I often heard about but never saw.

I worked for an email provider for about 15 years.  We used just about every
protocol you can think of to transfer mail to customers, including those
already listed plus Kermit / X/Y/Zmodem / Blast (a file transfer package few
seem to have heard of) wrapped up in protocols we came up with ourselves
which often also used stuff like Zip to compress the data for transmission.
We used them to feed mail into all sorts of email systems long since come
and gone, for example CCmail, Microsoft Mail and Pegasus Mail, to name but
three from the 1990s.

Perhaps it would be easier to come up with a list of protocols that were
never used to transfer email?  Fred! Help me out here!

Peter Coghlan

> -- 
> Grant. . . .
> unix || die

Chris Long wrote:
> This is tedious.

Maybe so but it's not as tedious as your response.

Btw, are we related?  There are Longs in my family tree.

Peter Coghlan.

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