read user emails from an account outside the azure users

Question

Hi,

We have created and set up an app on azure portal and have provide all the permissions required as per the documentation. We can read emails from the account we have logged in with or for users under the domain/teant.

What we need is: read emails of any external user that provides us the consent- any user that has an office 365 email account- can you point us to the right docs/steps for this.