This is something you or your club will need to do on your side, but it is quick and easy. Log in to your site and go to Reports>Email Reports. At this time there is only one emailed report. Click Edit and you will see everyone that receives that nightly email on the right side. Click the trash can next to each name you would like to remove from that nightly email.
If you don't have access to the Reports tab, an Administrator for your club will need to do this for you.