Event ID:1024
Source:MSExchange EdgeSync
Symbolic Name:EdgeLeaseException
Message:The connection to the ADAM instance of the Edge Transport server failed with exception "%1". This could be caused by a failure to resolve the Edge Transport server name %2 in DNS, a failure when trying to connect to port %3 on Edge Transport server %2, network connectivity issues, an invalid certificate, or an expired subscription. Verify the configurations of your network and server.

This Warning event indicates that an exception occurred when the computer that is running the Hub Transport server role tried to acquire a lock on the computer that is running the Edge Transport server role. A lock is required to make sure that configuration data is correctly replicated to an Active Directory Application Mode (ADAM) instance on Edge Transport servers. ADAM can only be replicated with configuration data from one Hub Transport server at a time.

This event may be logged because a subscription on an Edge Transport server is expired or disabled. The exception specified in the event description provides more information about this failure.

User Action

To resolve this event, re-subscribe the Edge Transport server specified in the event description. For more information, see Subscribing the Edge Transport Server to the Exchange Organization.

If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.