Hi InstaDRY
The Work Orders are assigned to the Customer rather than the Contact so these two fields won't be any help to you (it caught me out for a while too). If you add a linked field to the Activity table using Entity as below you should be able to get the Customer's Email onto your route sheet.
Here's how I got it to work for me:
Step 1 - Add the Linked Field to the Activity table
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Step 2 - Open up your report in Report Designer
Step 3 - Drag the new EntityEmail field across and format how you wish. Remember to save as a new version so you can revert if need be.
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Step 4 - In Method, set the new report as your default and there run it
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If you have any problems or further questions just sing out.
Jeff