We were able to login using the Application Sign in method, and after logging in, we were not able to find any functionality to read/send emails. PFB the attached image for your reference. The 'Page2' attachment depicts the page that just has a list of users in that group, but does not read emails from a particular email ID. Looking forward to your support.
Thanks in Advance.
Hello.
That functionality to Read/Send emails is not available on the Demo version.
You can find more information about the API and possible ways to implement it consulting the Microsoft API Docs