The Data Protection (DataMinder) Exchange Server Agent (ESA) Integration returns errors the following in the wgnesa_.log file.
E2F87 Policy Engine Hub, error 0x800700a4 (No more threads can be created in the system. ).
E2F8A Entering failure mode.
The Exchange Server integration comprises of two components the ESA (Exchange Server Agent) which integrates with Exchange and the the WGNPhub (Policy Engine Hub) which receives the event from the ESA and passes it to a PE (Policy Engine) to apply policy and action. The ESA will enter failure mode resulting from a serious failure to communicate with the Policy Engine Hub.
For example; This has been seen where the transport services have been reconfigured without recycling (restarting) the Exchange Hub Transport Service after the changes have been applied.
After the ESA is in failure mode the Wgnesa_.log files will fill up with failed event errors as the messages pass through the Exchange server. For example;
Nov 09, 2015 15:37:03.490E2F84Failed. Message: 'Monday Meeting'. Reason: 0xe5632f02 (The Agent is in failure mode. ).
To address this issue restart the Exchange Server Hub Transport server or reboot the server.