[comp.unix.admin] Controlling 'From' in mail headers? Help!

peter@java.sophia.com (Peter Espen) (04/23/91)

        I have a uucp connection to a machine that has access
to the internet.

        How can I get the 'From' address in my outgoing mail headers
to reflect an internet address instead of a banglist address that
shows the entire path that my message has taken?

        For example, if I send an outgoing message on my machine, it
is que'd for the internet connected machine with a 'From' line
that looks like:

        uucpmachine!peter

When this message goes out from the internet connected machine, the
'From' line in the header looks like this:

        netmachine!uucpmachine!peter

I want it to look like this:

        uucpmachine!peter@domain.com

so that people who get my message down the line will be able to
reply to  'uucpmachine!peter@domain.com'  instead of a long list
of uucp connections that they have to follow to get back to me.

        The sysop and I can change the sendmail configuration on the
internet connected system if that is what is needed, but we need help
on figuring out what to change!

        Anyone?

	peter@sophia.com

maine@altair.dfrf.nasa.gov (Richard Maine) (04/23/91)

On 22 Apr 91 18:51:41 GMT, peter@java.sophia.com (Peter Espen) said:

Peter> When this message goes out from the internet connected machine, the
Peter> 'From' line in the header looks like this:

Peter>         netmachine!uucpmachine!peter

Peter> I want it to look like this:

Peter>         uucpmachine!peter@domain.com

Peter> so that people who get my message down the line will be able to
Peter> reply to  'uucpmachine!peter@domain.com'  instead of a long list
Peter> of uucp connections that they have to follow to get back to me.

Sorry I am not fluent enough in sendmail.cf hacking to directly
answer your question, but I do have one suggestion for when you do
figure out how to hack sendmail.cf to your purpose.  I suggest you
try to make the from line show something more like

     peter%uucpmachine@domain.com

instead of

     uucpmachine!peter@domain.com

The form you suggested, with mixed uucp-style and domain-style addressing
is not standard and does not work with some mailers.  Even those mailers that
accept the format are not 100% consistent in how they interpret it.
Some interpret it as you intend (send the mail to domain.com and from
there to uucpmachine!peter).  Others interpret it to mean send the mail
to uucpmachine and from there to peter@domain.com (which won't work).
There is no standard to say which of these interpretations is correct.

The form I suggested is much more universally accepted.  (I won't claim
its entirely universal, but it seems like the most widely workable one).
There is also an RFC822 routine syntax that starts out like
"@domain.com:" (or that ":" might be a ";" - I forget), but I've had
mixed luck with using this syntax to bridge between domain-style and
uucp-style addressing.

I perhaps should have e-mailed this reply, but the issue comes up enough
that it seemed worth posting.

--
--
Richard Maine
maine@altair.dfrf.nasa.gov

fitz@wang.com (Tom Fitzgerald) (04/26/91)

> On 22 Apr 91 18:51:41 GMT, peter@java.sophia.com (Peter Espen) said:
> Peter> When this message goes out from the internet connected machine, the
> Peter> 'From' line in the header looks like this:
> Peter>         netmachine!uucpmachine!peter
>
> Peter> I want it to look like this:
>
> Peter>         uucpmachine!peter@domain.com

maine@altair.dfrf.nasa.gov (Richard Maine) writes:
> I suggest you
> try to make the from line show something more like
>
>      peter%uucpmachine@domain.com
>
> The form you suggested, with mixed uucp-style and domain-style addressing
> is not standard and does not work with some mailers.

Unfortunately the % form fails just as often.  In fact, we generally have
more luck with !-format addresses than %-addresses.  The problem is, if
the % address is ever given to a UUCP-only site running a smart mailer, it
will rewrite the address to pass through UUCP links, and wind up with:

	path!to!domain.com!peter%uucpmachine

If either of the machines 'path' or 'to' obey RFC 1123, they will try to
pass it directly to uucpmachine, skipping over domain.com entirely, and
the mail will fail.  Only machines that violate RFC 1123 in this respect
will forward the mail properly.

There are 2 rules of thumb here:

1) If the mail is destined to be forwarded through an ancient Sys V
   UUCP-only machine using the vendor's mailer, then  a!b@c  won't work.

2) If the mail is destined to be forwarded through a UUCP-only machine
   running a smart mailer, then through a site that obeys RFC 1123, then
   b%a@c  won't work.

In my experience, case #2 is much more frequent than case #1, making !-form
addresses more reliable than %-form addresses.

---
Tom Fitzgerald   Wang Labs        fitz@wang.com
1-508-967-5278   Lowell MA, USA   ...!uunet!wang!fitz

les@chinet.chi.il.us (Leslie Mikesell) (04/26/91)

In article <b4gzf5.9mo@wang.com> fitz@wang.com (Tom Fitzgerald) writes:

>1) If the mail is destined to be forwarded through an ancient Sys V
>   UUCP-only machine using the vendor's mailer, then  a!b@c  won't work.

Ancient in this case means any SysV as supplied by AT&T up to, but
not including release 4.  (As in almost everything currently available).

>2) If the mail is destined to be forwarded through a UUCP-only machine
>   running a smart mailer, then through a site that obeys RFC 1123, then
>   b%a@c  won't work.

>In my experience, case #2 is much more frequent than case #1, making !-form
>addresses more reliable than %-form addresses.

This must be a case of a specific mailer that unwinds % before @, which
I would consider to be wrong for anything that is supposed to be "smart".
The real solution is to get your own domain name if you want everyone
to be able to reply from/through the internet.  However, uunet's rewriting
approach is also fairly reliable if the sending site is in the maps.
They rewrite  a!b!c!u as c%u@uunet.uu.net, then when the reply comes
back to them, they will find c in the maps and route accordingly.

Les Mikesell
  les@chinet.chi.il.us

ires@kaspar.ires.com (Bruce R Larson) (04/29/91)

In article <b4gzf5.9mo@wang.com> fitz@wang.com (Tom Fitzgerald) writes:
>[ mucho deleted ]
>
>	path!to!domain.com!peter%uucpmachine
>
>If either of the machines 'path' or 'to' obey RFC 1123, they will try to
>pass it directly to uucpmachine, skipping over domain.com entirely, and
>the mail will fail.  Only machines that violate RFC 1123 in this respect
>will forward the mail properly.
>
The meaning of rfc1123 is not crystal clear on this issue.

Here is the offending passage fron Section 5.2.16:
``...  It is suggested that "%" have lower precedence than any
  other routing operator (e.g., "!") hidden in the local-part;
  for example, "a!b%c" would be interpreted as "(a!b)%c".''

On the one hand it suggests that "%" should have lower precedence
than "!", but on the other hand it suggests that "a!b%c" would
be interpreted as "(a!b)%c".  The former make much more sense
when "%"s are interpreted only in the local part of an address.

Bruce
-- 
Bruce R. Larson
Integral Resources, Milton MA
Internet:  blarson@ires.com
Uucp:  ..!{world|uunet}!ires.com!blarson

wrf@mab.ecse.rpi.edu (Wm Randolph Franklin) (05/04/91)

Some other mail packages, such as MH, let you specify your own From:
line.  I use this since I send from a local machine in my office but I
want people to mail to me c/o a bigger machine that is up more.

This doesn't resolve whether ! is better than %, but whichever you pick
you can put into your mail w/o modifying sendmail.cf.  Of course this
has to be done for each user separately unless you modify MH's post
command to do it.
-- 
						   Wm. Randolph Franklin
Internet: wrf@ecse.rpi.edu (or @cs.rpi.edu)    Bitnet: Wrfrankl@Rpitsmts
Telephone: (518) 276-6077;  Telex: 6716050 RPI TROU; Fax: (518) 276-6261
Paper: ECSE Dept., 6026 JEC, Rensselaer Polytechnic Inst, Troy NY, 12180