Two Exchange 2003 servers on same subnet unable to send emails to each other
Posted on 2008-11-06
I have two Exchange 2003 SP2 servers. One is on Windows 2003 server and the other on a Windows 2000 server.
We moved the Windows 2000 server from a remote location that is in the process of moving to a new building.
We placed the new Exchange 2003 on our existing subnet. Our internal Exchange 2003/Windows 2003 server was already operational on this LAN.
I have taken care of all the port forwarding, etc. and to the outside world the Exchange server works fine. However, it will not send email to my existing domain and I can't send email to the new domain.
Exhange 2003 SP2 on Windows 2003
Exchange 2003 SP2 on Windows 2000
If I attempt to email user@NewDomain.com, the SMTP connector doesn't send to the Exchange server handling NewDomain.com.
I watched my firewall traffic and realized I had missed the fact it was still resolving to our public IP.
On the two Exchange servers I created DNS Forward Lookup Zones for the other Exchange servers domain and created an A record and an MX record using the INTERNAL IP of the machine.
When I use NSLOOKUP | set q=mx and query for the domain (e.g. NewDomain.com), I get the INTERNAL IP address. However, when I try to force the connection from the SMTP server Queues list, my firewall logs shows the Exchange server trying to connect to the EXTERNAL IP on port 25. This happens on both servers.
I have flushed the DNS cache, rebooted the servers etc. with no change. This is causing issues because we send lots of email between the domains.
Any help will be greatly appreciated!!