DidTheyReadIt is a service that allows users to track emails to determine if and when they have been opened. It provides insights into email engagement by notifying the sender once the recipient has opened the email, including details such as the time, date, and location of the opening. This tool can be particularly useful for professionals who require confirmation on the delivery and receipt of critical communications. The service is accessible via its website, http://www.didtheyreadit.com/.