There are 3 main logs that are generated by ndMail.
ndMailApplication, ndMailApplicationJournal and ndMailOutlookAddIn.
Logs can be found at: C:\Users\username\AppData\Local\NetDocuments\ndMail\Logs
The ApplicationJournal Logs are errors specific to the actual filing process and the ndMail icon that runs in the system tray. Once the user clicks file in the client app in Outlook it hands it off to the application running in the system tray.
Logs recorded here cover the process of the client preparing to talk with the server and file the email. Then it tracks the process of completing the filing of the email.
This log is specific to the ndMail outlook add-in client. It generates logs based on errors it receives.
(ndMail supports Tracing the same as ndOffice)