Identify Leads That Have Reached Their Communication Limit
Issue
You would like to have a list of leads who will get blocked from receiving emails when you send email via campaign or program due to Communication Limits. Your Communication Limit setup can be found in the Admin Panel and looks something like this.

Solution
You can create a Smart List with the below setup and this list will show you the list of the people who will hit communication limit when you try to send an email.

To learn more about Communication Limits and how they work, you can review this article.