Controlling 'From' in mail headers? Help!

[Leslie Mikesell]

In article <b4gzf5.9mo at wang.com> fitz at 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 at 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 at 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 at uunet.uu.net, then when the reply comes
back to them, they will find c in the maps and route accordingly.

Les Mikesell
  les at chinet.chi.il.us