Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!ucbvax!ucdavis!iris!zerkle
From: zerkle@iris.ucdavis.edu (Dan Zerkle)
Newsgroups: comp.sys.amiga.datacomm
Subject: Re: Mail addresses...which one is correct?
Message-ID: <8993@ucdavis.ucdavis.edu>
Date: 18 May 91 02:58:54 GMT
References: <1991May16.131635.19878@ns.network.com>
Sender: usenet@ucdavis.ucdavis.edu
Reply-To: zerkle@iris.ucdavis.edu (Dan Zerkle)
Organization: U.C. Davis - Department of Electrical Engineering and Computer Science
Lines: 58

In article <1991May16.131635.19878@ns.network.com> guy@ns.network.com (Guy D'Andrea) writes:
>I have received mail many times and sometimes I do a "r" for reply while in 
>mail, I get the mail back.  It got to me, why can't I send the other way?

You are probably using Berkeley mail on an Unix system.  Your problem
is that the computer is not always smart enough to figure out the
proper address of the person who sent you the mail.  When someone
sends you mail, he doesn't always send his complete address, so the
mail system has to try to turn the address around.  For various
assorted reasons, it often screws up, especially if the message has to
go through several "hops" before it gets to its destination.

>On a simular note, I received a message in mail and saved it for later.  When
>I read it, it had different names for that person. (I tried them all and only
>got back the message saying it can't be delivered.

Very often, there is more than one way to get mail to some
destination.

>Can anyone tell me how to decifer these? 
>Like "someplace!somehow! guy@uunet.uu.net" or "ad897963-dads3@somewhere.here"?

Well, I don't want to give you a complete tutorial on this.  Go look
in alt.sys.amiga.uucp for Matt Dillon's posting that explains lots of
stuff about how to address mail.  If you can't find it, ask someone to
post it.  Also, ask around your local area for people that send a lot
of mail.  They will know how to do it.

someplace!somehow!guy@uunet.uu.net
Send the mail through the Internet to a very popular machine named
uunet.uu.net.  Uunet will send it through some combination of machines
to a machine named "someplace."  Someplace will connect directly
through uucp (probably a modem call) to a machine named "somehow,"
then somehow will deliver the mail to a user named guy.

ad897963-dads@somewhere.here
Send mail (probably through the internet) to some machine named
"somewhere" which is in the "here" domain.  That machine will deliver
the mail to a user cursed with the username "ad897963-dads."

If mail comes back to you, that is called a "bounce."  It means there
was some problem in delivering it, usually a reference to an unknown
machine (host).  In this case, look at the "Received:" lines in the
original message to you to determine what path the incoming message
took.  Based on this, it is possible to reverse the path and send the
mail the other way (usually).  Ask someone at your site to demonstrate
this to you.

Of course, the mail networks are so large and complicated, there are
regularly problems with them.  Sometimes, it just plain isn't possible
to send mail to someone, due to faults.  Sometimes, it's just too
complex to figure out, often when you see a Usenet post with a .UUCP
in the mail address.  This is why people should attatch signatures to
their posts giving a good email address with the name of a fully
domained (dots in the name) site in it.

           Dan Zerkle  zerkle@iris.eecs.ucdavis.edu  (916) 754-0240
           Amiga...  Because life is too short for boring computers.