Hello all. I've create my custom audit trail provider using Exchnage SDK Sample. I've register my AuditTrail provider as COM using regsvr32 Also i've set process definition property "http://schemas.microsoft.com/cdo/workflow/audittrailprovider" = MyWF.AuditTrail, where MyWF.AuditTrail is ProgID of my AuditTrail class. But wokflow eventSink generates an error in Application log when i'm trying to save any item to my workflow public folder. The error is: Workflow event sink error [event: OnSyncSave, URL: <file://./backofficestorage/myserver/Public Folders/MyWFFolder/No Subject.EML>]: The audit trail specified on the ProcessDefinition was either incorrect or couldn't be created: ?Z?Z Anyone knows what the problem is this? Thanks, Alexander.