I have a working Exchange 2K server that handles all my email on domain.com. I set up a second mail server running sendmail on RedHat Linux 7.3 so that I can use the Majordomo list server. I set up an Active Directory Contact that should forward emails sent to email@example.com to firstname.lastname@example.org.
However, my Exchange server sends back an email saying that "The destination server for this recipient could not be found in Domain Name Service (DNS). Please verify the email address and retry."
I can send messages to sendmail.domain.com from another sendmail instance on the same LAN, so I am assuming the problem is in the Exchange configuration. I have an internal DNS server and I know there is an MX record for sendmail.domain.com.
Thanks in advance for any help