I'm trying to get sendmail to forward to an internal mail server behind a firewall (both exchange and sendmail are behind the firewall, same network). The perl script sends to external address just fine, however, when trying to send to the internal mail server, I get the following bounced mail error codes:
Remote-MTA: DNS; [127.0.0.1]
Diagnostic-Code: SMTP; 550 5.1.1 <tech@ubifcu.com>... User unknown
I have mX records pointed at my mail server internally, but the e-mail keeps bouncing as if it thinks the Linux server is ubifcu.com
I do have my exchange server setup as the smarthost in sendmail.cf, and I can create an SMTP session via telnet.
Can anyone shed some light on this?
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