I've found various links for sending TestNG reports to be emailed after test executions here are two of the links
https://loganathan1988.wordpress.com/2014/11/03/how-to-email-automated-test-execution-reports-as-an-attachment-using-java-mail-api-in-selenium/comment-page-1/#comment-9 http://www.assertselenium.com/java/emailable-reports-for-selenium-scripts/
I've downloaded mail.jar as well but don't know how to configure all this with my project to send an email after test execution