Can I set up a monthly submission report to be automatically delivered to an email address?

Unfortunately no. However, you can check your Current Month Usage by going to your USAGE page https://www.jotform.com/myaccount/usage

Or you can also use this app to view your Submission History https://apps.jotform.com/app/submission_history_chart

You may also use Jotform's own Form Analytics https://www.jotform.com/blog/150-Introducing-Form-Analytics which gives more detailed report of your forms.

Hope this help, let us know if you need further assistance.