Working on implementing a POC to demonstrate the new e-Discovery capabilities in SharePoint and Exchange 2013 I hit an interesting issue which I could not find any resources online to troubleshoot. To setup the e-Discovery I successfully:
After provisioning an e-Discovery site ,I managed to successfully add a mailbox but then notice the following error on the page:
"This source may be invalid, you do not have permission to access this location, or the location is not indexed by Search."
Looking at the ULS log I noticed the following exception:
"ExecuteDiscoveryQuery: Query to Mailbox with Id [/o=ALIMAZ/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=12f2304707574b4c88a645db9e7c09e2-Administrator], IsArchive [True] failed with error code  and error message [Search AdminRpc call failed on Mailbox database instance 1b061d06-19a9-4fcd-b61b-9dcac1a1c97b with return code 2802.]"
After searching online and not finding anything related to the above error I suspected that our friend Exchange should be the cause of this error :), wearing my Exchange admin hat (Kinda scary) I saw the same error in the event log on Exchange server and running Test-ExchangeSearch cmdlet noticed that Content Index State for the mailbox database is in "FailedandSuspended" mode.
Following TechNet article Reseed the search catalog and manually resetting the index on Exchange resolved the issue and I managed to conduct queries against Exchange from e-Discovery site and wrap up the POC: