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Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!husc6!seismo!sundc!hqda-ai!merlin
From: merlin@hqda-ai.UUCP
Newsgroups: comp.mail.misc
Subject: Re: mail problems
Message-ID: <304@hqda-ai.UUCP>
Date: Wed, 25-Feb-87 15:38:40 EST
Article-I.D.: hqda-ai.304
Posted: Wed Feb 25 15:38:40 1987
Date-Received: Fri, 27-Feb-87 22:03:00 EST
References: <6661@alice.uUCp>
Organization: Army AI Center, Pentagon
Lines: 84
Summary: simple answers.  no flames, please.

In article <6661@alice.uUCp>, mvs@alice.UUCP writes:
> Lines of the form
> 
> 	Received: by xxx.yyy.UUCP (4.12/4.7)
> 		id AA12424; Mon, 16 Feb 87 14:09:06 est
> 
> are often added.  I've omitted the names as to not embarass
> the people at that site (Hello Laura!).  Surely these should be
> written to a log file and NOT into my mail item!

     The received header lines are added by every machine that
gets the mail.  You machine probably puts one in the message you
sent to yourself, but the mail program (the "user agent", as
opposed to the "delivery agent") doesn't show them to you.

     They should not be put in a log file.  The present method has
enough information to trace exactly where and when a mail message
was routed.  If it gets lost, it can be important to see that this
information does not get separated from the mail itself.  That's
why its included in the header lines.

> Often the "From" line gets horribly mutilated.  '%' signs crop
> up, which suggests to me that someone is screwing up a printf
> somewhere.  Some of the output looks like what happens when I
> printf bad pointers!

     In the internet (like ARPA, CSNET, BITNET) world, addresses
are of the form "mvs@alice".  There can be only one "@" in the
address.  The % is a sleaze that is used when a mailer really
wants to have two @ symbols, but the rules only allow one.

> Occaisonally a greater-than-sign '>' is prepended to a line in
> the body of the message, and sometimes the top of the item gets
> completely scrunted, particalularly my chess games.

     Many mail messages are held in the same file.  To distinguish
them, the mailers look for the header lines.  (Usually, they look
in particular for a line of the form

     	  From {address} at {time}

but others are in use.)  If you have a line in your message that
looks too much like this, it could mess up a mailer.  Thus, the
delivery agents (programs responsible for passing mail around to
different machines) put a ">" in front of these lines.  This keeps
the mail user agents (the programs that humans use to display
mail) from being fooled.

> Can anyone help me pinpoint the problem.  I wouldn't want to
> go screaming to the system administrator if it wasn't his fault!

It's not your system administrators fault.  In fact, it's nobody's
fault.  It's supposed to work this way.

> Where exactly is "seismo", it doesn't seem to be on my floor.
> Who is "mc" and where is his vax?

     Seismo is a machine (sun-3, I think) at the Center for
Seismic Studies in Washington, DC.  Basically Grand Central
Station for electronic communications on the east coast.  Almost
everything of any real interest goes through there.

     Mcvax is a VAX-11/750 in Amsterdam.  Much the same sort of
service as seismo.  Mcvax is responsible for all of the netnews
distribution in Europe.

     Both of these machines are well-connected to many different
networks.  They do a great service to the rest of us by acting as
gateway machines.  (Gateways are systems that pass messages back
and forth between different networks.)
 
> Aren't there maps of these things?

     Yes, there are.  They're published every month on the Usenet
news system, in the group "mod.map".  Most of the information is
presented in a somewhat cryptic form.  It's intended for the use
of software that routes mail automatically, so you never have to
look at the maps.

-- 
	David S. Hayes, The Merlin of Avalon
	PhoneNet:	(202) 694-6900
	ARPA:		merlin%hqda-ai.uucp@brl.arpa
	UUCP:		...!seismo!sundc!hqda-ai!merlin