Hi, What you are asking for is called masquerading (people on hosta.foo.com are trying to masquerade as people from foo.com). This was easy even in pre m4 das of sendmail configuration, and in these new days of m4 ease this is a piece of cake.
This /etc/mail/sendmail.mc shall implement what you want (put this on hostb.foo.com, and make sure that mail sent to foo.com from the outside works). I've also set it so that mail sent to [EMAIL PROTECTED] shall be delivered locally (no need to hop from a to b to a). I have commented out the anti-spam stuff I use for myself. I hope this helps. manoj ====================================================================== divert(-1) # # Copyright (c) 1983 Eric P. Allman # Copyright (c) 1988, 1993 # The Regents of the University of California. All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # 1. Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # 3. All advertising materials mentioning features or use of this software # must display the following acknowledgement: # This product includes software developed by the University of # California, Berkeley and its contributors. # 4. Neither the name of the University nor the names of its contributors # may be used to endorse or promote products derived from this software # without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. # # # This file is used to configure sendmail for use with Debian systems. # divert(0) VERSIONID(`@(#)sendmail.mc 8.7 (Linux) 3/5/96') OSTYPE(debian)dnl FEATURE(masquerade_envelope)dnl FEATURE(use_cw_file)dnl FEATURE(use_ct_file)dnl FEATURE(redirect)dnl define(`confME_TOO', True)dnl MAILER(local)dnl MAILER(smtp)dnl Cwfoo.com MASQUERADE_AS(foo.com)dnl ## Custom configurations below (will be preserved) #HACK(use_ip) #HACK(check_rcpt4) #HACK(check_mail2) ====================================================================== -- "Just because you understand what something should look like doesn't mean you know how to build it." [EMAIL PROTECTED] Manoj Srivastava <[EMAIL PROTECTED]> <http://www.datasync.com/%7Esrivasta/> Key C7261095 fingerprint = CB D9 F4 12 68 07 E4 05 CC 2D 27 12 1D F5 E8 6E -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .