Here's the scenario:
Company A has a Windows 2003 domain with their own Exchange 2003 server. email domain is companya.com
Company B is a subsidiary of a much larger company. They have their own windows 2000 domain server and got their email through the exchangeb server of their parent company. email domain is companyb.com
Company A aquires Company B, but wants to conmtinue letting run as a separate entity. Company B keeps their domain server, but now gets their email through Comnpany A's Exchange server (they were setup as a separate OU in AD). MX record was changed to point to company A's Exchange server.
This all occurred several weeks ago, and all has been working fine - ALMOST!
It seems that randomly, some email messages (new and replies) meant for a companyb user is bounced back to the sender with a message that the recipient does not exist (but it does). The interesting part is that just below that bounceback message is referenced company B's old email servername. It's as if some random messages are getting routed to company B's old server. The MX record is correct and it's been several weeks, so I would expect all DNS servers to be up-tp-date.
Running a DNS report at dnsstuff.com does not show any problems (just a warning about not having an SPF record).
Any suggestions on how to troubleshoot this?
Company A has a Windows 2003 domain with their own Exchange 2003 server. email domain is companya.com
Company B is a subsidiary of a much larger company. They have their own windows 2000 domain server and got their email through the exchangeb server of their parent company. email domain is companyb.com
Company A aquires Company B, but wants to conmtinue letting run as a separate entity. Company B keeps their domain server, but now gets their email through Comnpany A's Exchange server (they were setup as a separate OU in AD). MX record was changed to point to company A's Exchange server.
This all occurred several weeks ago, and all has been working fine - ALMOST!
It seems that randomly, some email messages (new and replies) meant for a companyb user is bounced back to the sender with a message that the recipient does not exist (but it does). The interesting part is that just below that bounceback message is referenced company B's old email servername. It's as if some random messages are getting routed to company B's old server. The MX record is correct and it's been several weeks, so I would expect all DNS servers to be up-tp-date.
Running a DNS report at dnsstuff.com does not show any problems (just a warning about not having an SPF record).
Any suggestions on how to troubleshoot this?
