...
Right click on the headings in your Outlook program (e.g. From, Subject, Received etc)
From the drop down choose View Settings
From the pop up, click on Columns. This will take you to page that allows you to customise your columns.
Click on the drop down with the current value of 'Frequently-used fields' and choose 'User-defined fields in inbox'
This will change your available columns to only show the heading related to your saved OWL documents. Choose WOL Matter and then select the Add button.
Press OK and then OK again to save and get out of the Columns.
You should now have a WOL Matter Column available in your headings bar that will display the matter that the email is saved to once it is saved.
...