Exchange 2010 running on Server 2008 Active directory Domain name: domain.com exchange email domain: rebranded.com Messages sent to old email addresses on hosted emai server user@domain .com are returned with the following error: Diagnostic information for administrators: Generating server: EXCHANGESRV1.domain.com user1@domain.com #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ## Original message headers: Received: from EXCHANGESRV1.domain.com ([10.1.x.x]) by exchangesrv1 ([10.1.x.x]) with mapi; Tue, 4 May 2010 10:15:29 -0500 Content-Type: application/ms-tnef; name="winmail.dat" Content-Transfer-Encoding: binary From: user<user@rebranded.com> To: user2 <user2@domain.com> Subject: test2 Thread-Topic: test2 Thread-Index: AcrrnKGcBmsQ5uy4QNuu34Ecj/f1nw== Date: Tue, 4 May 2010 10:15:29 -0500 Message-ID: <250BBAFCB272B34F859D24CFBCED48B00A7CD2@mk-exchangesrv1> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: <250BBAFCB272B34F859D24CFBCED48B00A7CD2@mk-exchangesrv1> MIME-Version: 1.0 How can i get these messages to send?

Exchange 2010 running on Server 2008 Active directory Domain name: domain.com exchange email domain: rebranded.com Messages sent to old email addresses on hosted emai server user@domain .com are returned with the following error: Diagnostic information for administrators: Generating server: EXCHANGESRV1.domain.com user1@domain.com #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ## Original message headers: Received: from EXCHANGESRV1.domain.com ([10.1.x.x]) by exchangesrv1 ([10.1.x.x]) with mapi; Tue, 4 May 2010 10:15:29 -0500 Content-Type: application/ms-tnef; name="winmail.dat" Content-Transfer-Encoding: binary From: user<user@rebranded.com> To: user2 <user2@domain.com> Subject: test2 Thread-Topic: test2 Thread-Index: AcrrnKGcBmsQ5uy4QNuu34Ecj/f1nw== Date: Tue, 4 May 2010 10:15:29 -0500 Message-ID: <250BBAFCB272B34F859D24CFBCED48B00A7CD2@mk-exchangesrv1> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: <250BBAFCB272B34F859D24CFBCED48B00A7CD2@mk-exchangesrv1> MIME-Version: 1.0 How can i get these messages to send? Can u verify that this recipient exists in your server using following PS command: Get-Recipient user1@domain.com Regards,Laeeq Qazi|Team Lead(Exchange + Sharepoint + BES + DynamicsCRM) www.HostingController.com

Running Get-Recipient user1@domain .com i get: Name RecipientType ---- ------------- User1 UserMailbox But the user1.domain.com mailbox is actually on a POP/SMTP hosted email server outside our network

Quote: “But the user1.domain.com mailbox is actually on a POP/SMTP hosted email server outside our network” In the diagnostic information, the recipient is user2, not user1 Is this an internal mail flow issue? Please describe more about exchange server and POP/SMTP topology Is there any third party software on the exchange server? Resources: Configure Exchange 2010 to Route Messages for a Shared Address SpaceJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com

Resolved: I modified the Default E-mail address policy to use the rebranded.com domain Removed domain.com from accecpted domains created a send connector for domain.com that uses external DNS MX records