Email01 is a traditional application that only uses the mail function, which is used by the SendMail application (a reactive application). So the Email01 application cannot run alone. Users must install the SendEmail application. SendEmail and Mail01 applications are inspired by a video on YouTube entitled OutPower Tutorial - Reactive web application - Sending an Email (OutSystems). Which has been slightly modified. Link : https://youtu.be/ks5CbksqED8.