tcchao@watcsc.waterloo.edu (T C Chao) (10/27/90)
_________________________________________________________________ Could someone out there help me out with this simple question? Q: When you send email to someone else, you often have to type "@" or "!" or "%" key between the dosite names, domain names... Would somebody give me a full description of "@", "!" & "%" and give me some useful examples. Thank you very much (I apologize if I had posted up in a wrong newsgroup)
stealth@caen.engin.umich.edu (Mike Pelletier) (10/29/90)
In article <1990Oct27.010347.13485@watcsc.waterloo.edu> tcchao@watcsc.waterloo.edu (T C Chao) writes: > >_________________________________________________________________ > >Could someone out there help me out with this simple question? > >Q: When you send email to someone else, you often have to type > "@" or "!" or "%" key between the dosite names, domain names... > Would somebody give me a full description of "@", "!" & "%" > and give me some useful examples. @ - stands for "at" such as "user@host.domain". ! - addresses including these are usually called "bang-paths," "bang," since the exclamation point is typically prounouced "bang," and the "path" part comes from the fact that such addresses specify an explicit route for the message to take from machine to machine to reach its destination. Thus, "uunet!mailrus!umich!caen!b-tech!m-net!stealth" would hand a message from machine "uunet" to "mailrus", and from there down the path until it gets to "m-net!stealth" -- my mailbox on M-net. % - sort of a reverse bang, in a way... The address in the previous example could be rewritten as "stealth%m-net%b-tech%caen%umich%mailrus@uunet.uu.net". When the message reaches uunet, the "@uunet.uu.net" would be removed and the @ sign would be moved to the leftmost % sign, the resulting address processed, and the message sent along. The same thing would happen at each stage, until b-tech has a message to "stealth@m-net", which it could then deliver to M-net, and thus it would end up in my mailbox there. Hope that helps... -- Mike Pelletier - Usenet News Admin & Programmer "Wind, waves, etc. are breakdowns in the face of the commitment to getting from here to there. But they are the conditions for sailing -- not something to be gotten rid of, but something to be danced with."
mathisen@dali.cs.montana.edu (Jaye Mathisen) (10/29/90)
In article <1990Oct28.210632.26119@engin.umich.edu> stealth@caen.engin.umich.edu (Mike Pelletier) writes: > be removed and the @ sign would be moved to the leftmost ^^^^^^^^ shoule be rightmost
piet@cwi.nl (Piet Beertema) (10/30/90)
> % - sort of a reverse bang, in a way... The address in the > previous example could be rewritten as > "stealth%m-net%b-tech%caen%umich%mailrus@uunet.uu.net". That may be true in some places, but not in others. Since the %-part in user%localhost@yourdomain often is a locally meaningful entity, there are mailers around that try to preserve it when rewriting such addresses to !-style (yourdomain!user%localhost), since that's the only way to rewrite it from @-style to !-style *and* vice versa without loss of information. Please note that this is meant to present facts, not a call for discussion. -- Piet Beertema, CWI, Amsterdam (piet@cwi.nl)
wnp@iiasa.AT (wolf paul) (10/30/90)
In article <1990Oct28.210632.26119@engin.umich.edu> stealth@caen.engin.umich.edu (Mike Pelletier) writes: > > % - sort of a reverse bang, in a way... The address in the > previous example could be rewritten as > "stealth%m-net%b-tech%caen%umich%mailrus@uunet.uu.net". > When the message reaches uunet, the "@uunet.uu.net" would > be removed and the @ sign would be moved to the leftmost > % sign, the resulting address processed, and the message > sent along. The same thing would happen at each stage, > until b-tech has a message to "stealth@m-net", which it > could then deliver to M-net, and thus it would end up in > my mailbox there. What you describe is what I understand is supposed to happen. However there are a bunch of sites out there where "%" gets translated into actual "!", so that the above path becomes "stealth!m-net!b-tech..." which is wrong. The mailer at the Austrian backbone refuses to send mail to any bang path where it cannot identify all sites specified in it, so I tried to send mail to an unmapped site as user%unmapped_site@their_mapped_feed.somename.com which got translated to user!unmapped_site@their_mapped_feed.somename.com which the mailer at their_mapped_feed interpreted as user@their_mapped_feed.somename.com and promptly rejected, since "user" did not have an account on their system. -- Wolf N. Paul, UNIX SysAdmin, IIASA, A - 2361 Laxenburg, Austria, Europe PHONE: +43-2236-71521-465 FAX: +43-2236-71313 UUCP: uunet!iiasa!wnp INTERNET: wnp%iiasa@relay.eu.net BITNET: tuvie!iiasa!wnp@awiuni01.BITNET