What must you generate to utilize the Email Service in your application?

To utilize the Email Service in your application, generating Binding Keys is essential. Binding Keys are used to authenticate and authorize communication between your application and the Email Service. These keys ensure that the application has the necessary permissions to send emails on behalf of the user or application, enabling secure operations within the Mendix environment.

The other options do not directly relate to the requirement for utilizing the Email Service. Session Keys typically pertain to user session management, Access Tokens are mostly used for securing APIs and ensuring made requests are authorized, and Email Templates, while important for crafting the emails, do not relate to the authentication or connection aspect required to use the Email Service.