When you install the Exchange 2007 Hub Transport server role, there will be created by default an invisible and implicit intra-organization send connector, which will enable mail flow between Hub Transport servers, located in different Active Directory sites. If you want to enable protocol logging for these connectors to be troubleshoot or keep-an-eye on mail flow to other Hub Transport servers in the same Exchange organization, to other Exchange 2003 servers in the same Exchange organization, or to Edge transport servers, you need to run the following Exchange Management Shell cmdlet Set-TransportServer and included the parameter IntraOrgConnectorProtocolLoggingLevel and set its value to Verbose. The information will be written to the Send Connector log file.