How to solve the 'Source Key is Invalid of Message' message

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Written by Support InfoBridge


When checking the logfile, you might see the message:

"WARNING ExchangeIdentifierResolver: Source key is invalid of message: ....."

How to:

This could mean that an item is deleted and does not exist in Exchange anymore. The Synchronizer tries to retrieve the Source Key on an item which no longer exists. This happens when a user deletes the item before the Synchronizer was able to delete it.

Another cause for invalid key codes could be because the Exchange Cache Mode is turned on. Please check the (MAPI) Profile in the Technical Settings in the Synchronizer Admin.

This is a Warning only message, no synchronization problems are to be expected.


This article also applies to:

  • Exchange Online Synchronizer
  • Outlook (Online) Synchronizer