Here is my configuration (and a letter "A" is in fact a mailing symbol AT, but I can't post it like that ) :
sendmail-8.13.1-3.2.el4
procmail-3.22-14
RHEL4U5

The problem is with address from which the autoreply message is being sent.

Under folder /home/user there are two files : .autoreply (where is the message text) and .procmailrc where is the procmail for autoreply.

So .procmailrc looks like this :

less .procmailrc
SHELL=/bin/bash
#
:0 h c
* !^FROM_DAEMON
* !^X-Loop: testAtest.net
| (formail -r -I"Precedence: junk" \
-A"X-Loop: testAtest.net" ; \
cat $HOME/.autoreply \
) | $SENDMAIL -t
(END)

And it works, returning to the sender the text from .autoreply file. BUT it send this text from the mail account which looks like this : name-from-/etc/passwd-fileAserver-hostname instead (in my case) testAtest.net

Under webmail (squirrelmail) the reply address is set as it should be.
I looked up a bunch of Internet pages, to no avail...
Also masquerade is not a option because my production system has two mail domains...

Ideas???