If you are running Exchange 2016 coexisting with legacy versions like Exchange 2010 or 2013, you might come across errors logged with regards to MsExchDiscovery. Here is a snippet of the error:

The solution?

Move the mailbox to the Exchange 2016 database. To do that open up the Exchange Management Shell and run the following command, the easiest being moving all arbitration mailboxes:

  • Get-Mailbox -Server <Exchange 2010 Server> -Arbitration | New-MoveRequest -TargetDatabase <Exchange 2016 Server DB>

Wait for it to finish and the error should be gone.

Hope it helps.