Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!orc!inews!iwarp.intel.com!gargoyle!chinet!les
From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: comp.mail.misc
Subject: Re: Smail 3.1 Mailing Lists -- Reply-To????
Message-ID: <1991Feb07.154817.1580@chinet.chi.il.us>
Date: 7 Feb 91 15:48:17 GMT
References: <1991Feb6.161404.28382@coplex.uucp> <121545@uunet.UU.NET>
Organization: Chinet - Chicago Public Access UNIX
Lines: 50

In article <121545@uunet.UU.NET> kyle@uunet.UU.NET (Kyle Jones) writes:
>dean@coplex.uucp (Dean Brooks) writes:
> >    When creating a "mailing-list" using the ":include:" structure
> > inside the aliases file, is it possible to have smail make the Reply-To:
> > appear to be the mailing list name?  Or perhaps the From:
> > line?

>Please don't do either of these things.  The From header shoudl
>reflect who the mail really is from.  And the Reply-To header is
>for the author's use, not the use of forwarding agents such as
>mailing list exploders.

>If you make the From or Reply-To headers point at the mailing
>list, you make it difficult for subscribers to reply to just the
>author of the message.  If you leave the headers alone the reply
>and reply-all commands of most mailers will do the expected
>thing.  Reply will use From or Reply-To, and reply-all will these
>plus the contents of the To and Cc headers, one of which will
>presumably contain the mailing list address.


There are some problems any way you try to handle this, mostly due to
lack of compatibility among mailers.  
If you simply leave the message alone and forward it to everyone on the
list, delivery error messages will go back to the sender who is unlikely
to be able to do anything about the bad addresses in the list.  If everyone
ran sendmail perhaps you could use the Errors-To: header.  They don't.
Another recently-posted message shows how to get the "Envelope-From" of the
message to point to the list maintainer, so the error messages will go there
instead.  However, lots of UA's on uucp machines generate replies
back to the Envelope-From (the From_ line in uucp mail), since that is
often more likely to work than whatever your neighboring site did to
the "From: " line.  So you're going to get some replies tossed at the
list maintainer. 
Also, I haven't seen a mailer that allowed replying only to the "To:"
address, so the reply will include a copy to the sender who is
undoubtedly also on the list.  Some software is smart enough to transport
a single copy back to the list exploder which might be able to figure
out that there is a duplication and eliminate it.  Only some...
Many UA's on uucp machines will generate replies to the To: and Cc: headers
by evaluating the From_ line to generate a path back to the sending
machine to be sure the address is evaluated in the same context as
when originally sent.  This means that if you do not rewrite the From_
line at the list exploder site, the reply is likely to be routed back
through the senders site before going to the list exploder (and replies
to the reply will keep growing longer paths).
Does anyone have a universal solution?

Les Mikesell
  les@chinet.chi.il.us