I've inherited an Exchange server running on SBS 2003. This server is supposed to be receiving mail via standard incoming SMTP for 2 domains, for the sake of this discussion let's call them abcltd.com and xyzltd.com.
The server was first set up with a local AD domain abc.local. It was first associated with the external domain abcltd.com. I'm told incoming mail worked fine up to "about 8 months ago" for that domain. However, incoming mail is no longer working for that domain.
At some point, the second domain xyzltd.com was added to the Exchange server. Incoming mail via that domain is working fine at this time.
I've been using the convenient testexchangeconnectivity.com site to test incoming SMTP mail.
There are some complications in mail routing to the server. There are 2 separate internet connections at the office, with a separate router for each. However, connectivity seems to be set up correctly: DNS MX records are correct, SMTP port 25 forwarding is set correctly to the server.
I was able to install the NetMon 3.4 packet sniffer on the server. SMTP traffic reaches the server during tests on both the domains. For the successful domain xyzltd.com, the capture log shows a standard SMTP conversation, interacting with inetinfo (which I understand hosts the Exchange SMTP Virtual Server) on the server. This is confirmed by activity in the Exchange server SMTP log.
For tests to the unsuccessful abcltd.com domain, the capture log shows fewer packets, and none of them interact with inetinfo. No activity is logged in the Exchange SMTP log.
My understanding from other Exchange 2003 installations supporting multiple domains is, to make them work all you need to do is:
This all appears to have been set correctly in this case.
- Make sure DNS MX records are correct
- Make sure routers etc. are set up so incoming traffic can reach the server
- Add the new domain to an appropriate Recipient Policy
- Apply the Recipient Policy
- Check for new SMTP addresses for recipients, add if necessary
My thinking at this point is, there is either a problem with Exchange configuration, or another process running on the server is causing interference.
The SBS installation seems fairly "vanilla", in a single-homed (not dual-homed) configuration. I've looked at server NIC settings and SMTP Virtual Server properties, I don't see anything that would cause incoming traffic for one domain to work, but the other to fail.
RRAS is not running on the SBS server. I don't see any 3rd party firewall or routing software installed (other than as noted below).
Symantec Endpoint Protection is running on the server. However, its firewall is not configured to do anything special. I have also tested with it turned off, that had no effect.
A "MailArchiva" mail archiving server is installed and running on the SBS server, but it does not appear to have ever been configured. I have also tested with its service stopped, that also had no effect.
At this point I'm stumped. All I can think to try is to remove abcltd.com from Recipient Policy, update, then add it back in again in the hopes that this may cure any weirdness deep in Exchange's bowels. I'm a little reluctant to do that, in case it causes issues with Active Directory, seeing as that domain is the one associated with the original installation of the SBS server. Can anyone advise about this?
Also, before doing that, can anyone advise about any obscure Exchange settings that could be checked or tweaked, or SBS settings that could be causing this issue?