Creating email merge reports are similar to other merge reports apart from one additional step.
Select an Email Address Field
To run an email merge, you need to ensure you have included an email field in your data extract.
And you need to make sure it is then selected in the Email Address Field combo box.
This tells Martial Class that you want to run an email merge and who to address each email to.
When you then execute this report (provided you have attached a word template to the report), Martial Class will run an email merge using word and Outlook rather than running a normal mail merge.