Symptoms
Riva cannot connect to a user’s Exchange mailbox, and the following error appears:
Connection to Exchange Server failed: [Unauthorized] [CannotImpersonate] Unable to resolve mailbox:
Cause
This error typically indicates an issue with the affected user’s Exchange mailbox that prevents Exchange from resolving the mailbox for access by Riva.
Resolution
Your internal Exchange team is the best starting point for resolving this error. Share the full error message and the affected user’s email address so they can check that the mailbox is available and configured for access by Riva.
Once any mailbox issues have been resolved, retry the connection.
If you’re still seeing the error, contact the Riva Technical Support Team. Please include the full error message, the affected user’s email address, and any findings or changes from your Exchange team’s review.