[LINK] Why www.etc?

[Paul Brooks]

Jan Whitaker wrote:
> At 10:52 AM 6/12/2007, Glen Turner wrote:
>>   gdt at its  -- if the sender was in the University of Adelaide
>> and this was seen as an advantage in an age where e-mail addresses were
>> typed.
>
> This approach to email also mimics real mail. It made it quite easy 
> for me to teach people how to conceptually construct one. Doesn't mean 
> they got them typed correctly as there is no standard except for the 
> @, country code, and the top level domain. Every other component can 
> be almost anything that avoid the set of special characters. Even the 
> @ I believe can be substituted with +. I just learned that recently 
> when setting up a new email account, but that may not be universal.
>
> Jan
The '+' is a fairly recent development used only within the Cpanel 
webhosting system as far as I know.

Use of the alternative character '%' dates back to the 1970s/1980s when 
some form of user-specified routing to relay gateways between different 
(non-RFC-821) email systems like BITNET, UUCP, ACSNET was required - 
'user%host1 at gateway.internetdomain' meant 'send the message to the host 
'gateway.internetdomain' first, which will understand how to gateway the 
message into the non-RFC882 email system and deliver to 'user%host' in 
the other email system. Possibly the gateway would replace the '%' with 
a '@' on the way through  if the second email system was also using 
Internet-style addresses.

This style of manual routing can still work today, but is usually 
blocked by anti-third-party-relaying rules introduced to block spam.

Back in the dark mists of time before the DNS, UUCP email was routed 
specifying the path using '!' as the separator - to get to user 'grg' 
the syntax was  'utzoo!decvax!harpo!eagle!mhtsa!ihnss!ihuxp!grg', 
assuming you were logged into host 'utzoo' at the time. In this system 
you had to specify the host closest to you, then the next closest, and 
so on,  which made things fairly short if you were trying to reach 
someone within your department or institution - and in the old days, the 
80/20 rule of local/long-distance ratios applied - the majority of email 
was to people within your own organisation. (Possibly this was 
self-fulfulling - sending an email to someone a long way away in network 
topology terms was so fraught with uncertainty that many were turned off 
trying!)

http://www.livinginternet.com/e/ew_addr.htm  provides a fairly concise 
summary of the history (and the example above).

A little bit of trawling found a list of old email addresses that 
demonstrates almost every conceivable combination of these forms at 
http://www.netlib.org/misc/groups

including gems like           "mfci!fisher%uucp"@yale.arpa   and     
"munnari!uacomsci.ua.oz!elhay"@uunet.uu.net  who was one of my CompSci 
lecturers at Adelaide Uni.


Regards,
    Paul.