For Deleting Schedule Jobs in Campaign
Go to that particular campaign
Click on Schedule via MassMailer Button
Click on Schedule Later button
Uncheck Schedule checkbox(screenshot attached Scheduled campaign)
For Deleting Schedule Jobs in Mass Email Wizard
Go to MassMailer Email Statistics tab.
In right hand side of screen select Recently Created. Next to view select ALL and click on GO. (screenshot attached MassMailer Email Statistics tab)
Select Schedule jobs that you want to delete and then click on Delete button(screenshot attached Delete schedule jobs)
MassMailer Team