How to log in Office365 keeping our own app login from an MVC ASP external application?

Hi All,

We want to log in Office365 keeping our app login in order to manage different organizations from a unique MVC ASP application. We have only found code to log in Office365 using the Office365 credentials for a unified login way. We intend to manage serveral companys in the same application, so this option is not valid for us. Also, not all that companys need to have an Office365 account.

As an example:

• A user launches the app and logs in our environment (using our login credentials).
• The app validates the user against the Office365 user account (using the Office365 credentials).
• Then, our app can Access the user email in Office365.

Is there a way to do this?

Thanks id advance,

A.Afonso