Once you are satisfied with the list of recipients, click Next; on the next screen you can opt to add an attachment to the Mail Merge.
Click Finish in the bottom right hand corner of the screen to close the Mail Merge Wizard and cue the Mail Merge to be sent at the time and date you defined in Step 1.
Once a Mail Merge has been sent from the system, you will be able to view it on the Mail Merge screen, where all historical Mail Merges are stored.