What does it mean when "authorization failure by user: " appears in the system log?

Issue

What does it mean when "authorization failure by user: ???" appears in the system log?

Solution

At the end of an NDMP image restore the mail store is off-line until the appliance is rebooted. Because the store is off-line the database containing the information needed to perform any authentication is unavailable and all attempts to authenticate a user fails.

Some DMAs (NDMP clients) attempt to connect to the NDMP services running on the Mirapoint appliance for reasons other than performing or completing a restore after the restore is started. These connection attempts fail with "authorization failure by user: ???" appearing in the system log.