Steps to register your application at Microsoft Office 365

Select New registration. On the Register an application page, set the values as follows:

• Set Name to a friendly name for your app.
• Set Supported account types to Accounts in this organizational directory only.
• For Redirect URI, change the dropdown to Public client (mobile & desktop) and set the value to https://login.microsoftonline.com/common/oauth2/nativeclient

Click on Register. On the next page, copy the value of the Application (client) ID and Directory (tenant) ID and save them, you will need that later.

Select Add a permission. On the Request API permissions page, select Microsoft Graph.

Select Application permissions and then select:

• Mail.Read

• Mail.ReadWrite

• Mail.Send

  

Click on Add permissions

Select Grant admin consent for org and click on the Yes button in the consent dialog.

Under Manage, click on Certificates & Secrets from the left-hand navigation pane.

Select New Client Secret, add a  small short description and select Add.

Copy the value of the newly added client secret and save it, as you will need it later.