The PureMessage Activity Monitor or ExchangeStoreScan.log contains the below error:
PureMessage store scanning has encountered an application error (details: 'Unknown error')
First seen in
PureMessage for Microsoft Exchange 4.0
The Exchange Web Services (EWS) based store scan is attempting to access an unrequired item and causing a NullReferenceException error.
What To Do
- Download and install PureMessage for Exchange version 4.0.2 which resolves some instances of this issue
- If the error is still met with version 4.0.2 then contact Sophos Support for further assistance