Hi, Following links may help to find out exchange 2003 mail relay settings; http://www.twistround.com/faq/faqs/E2k3Relay/E2k3Relay.aspx http://support.microsoft.com/kb/895853 Exchange 2003 and Exchange 2007 can both route to a connector that is hosted by either Exchange Server version. However, because of schema differences in connector configuration, some settings of the Send connector on an Exchange 2007 server will not be recognized by an Exchange 2003 server, and some settings on an SMTP connector on an Exchange 2003 server will not be recognized by an Exchange 2007 server. http://technet.microsoft.com/en-us/library/bb125223(v=exchg.80).aspx Thanks SaleeshIf answer is helpful, please hit the green arrow on the left, or mark as answer.

Hi, Following links may help to find out exchange 2003 mail relay settings; http://www.twistround.com/faq/faqs/E2k3Relay/E2k3Relay.aspx http://support.microsoft.com/kb/895853 Exchange 2003 and Exchange 2007 can both route to a connector that is hosted by either Exchange Server version. However, because of schema differences in connector configuration, some settings of the Send connector on an Exchange 2007 server will not be recognized by an Exchange 2003 server, and some settings on an SMTP connector on an Exchange 2003 server will not be recognized by an Exchange 2007 server. http://technet.microsoft.com/en-us/library/bb125223(v=exchg.80).aspx Thanks SaleeshIf answer is helpful, please hit the green arrow on the left, or mark as answer.

Mail loop is happening BTW Exch2003 Org and Exch2003 Org . 1. Where is mail relay setting in Exch2003 server ? 2. One Exch2003 Org include Exch2007, if in Exch2007 ,the relay was configured, it apply to all Exch2003Org ?