The Email Listing report lists contact and student email addresses for each family/account. It is frequently used to create a list to upload into an external marketing program.
From the Reports menu > Find Reports you will find the Email Listing report in the Email / Text / Marketing and Families / Students categories.
The report can be exported into Excel (or a .csv file) to upload to an email marketing program, such as Constant Contact or MailChimp.
Where this report's main purpose is to list email addresses, there are many more reports in Jackrabbit that will also give the email address.