I hope someone can help after spending 2 days searching everywhere. We'retrying to add a second domain to my client's Exchange server. The MX record is set up and working fine (confirmed with dnsstuff.com, also can telnet in using the MX record). The domain, let's say wxyz.com,has been added to recipient policies, Automatically updateis checked, and all users in ADgot the new addresses (i.e.jon@wxyz.com) But when I send an email to the new user the response is: The following message to <jon@wxyz.com> was undeliverable. The reason for the problem: 5.1.0 - Unknown address error 550-'5.1.1 Bad destination mailbox address (jon@wxyz.com) If I telnet to the server, the dialog is: ehlo250-webmail.abcd.com Hello [74.132.190.8]250-TURN250-ATRN250-SIZE250-ETRN250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-8bitmime250-BINARYMIME250-CHUNKING250-VRFY250-X-EXPS GSSAPI NTLM LOGIN250-X-EXPS=LOGIN250-AUTH GSSAPI NTLM LOGIN250-AUTH=LOGIN250-X-LINK2STATE250-XEXCH50250 OKmail from: cwood@efgh.com250 2.1.0 cwood@efghcom....Sender OKrcpt to: jon@wxyz.com550 5.7.1 Unable to relay for jon@wxyz.com The user jon has the address jon@wxyz.comin AD. I can send mail to his primary address, jon@abcd.com, just fine. Every article I find regarding "unable to relay" relates to relaying to an external domain. None seem to address the issue of getting this error for a domain name that has been defined in Exchange. Thanks in advance for your help!

Hi, If you can find the MX record on the net, then I think your second domain is set properly. But as you tested, there are obviously problem with "unable to relay". Did you test that command in your exchange server ? So in my opinion, you first check your relay option on ESM. ( Did you check this already ? ) You can alsoenable users who are in your organization to relay or not. And if you use "SMTP connector", then you have to check that property related to "relay" setting. please refer to document below. http://support.microsoft.com/kb/260973/en I hope this would be helpful :-) -MG