Configure the Google Domain

Register your domain name with Google, such as yourcompany.acme.com.
Log in to the Google domain using your domain administrator account to set up the domain to use Google Apps for Work.
After you log in to the dashboard (or portal) for administering your account, access the Admin console (for example, access admin.google.com).
Select Security.
Select Advanced settings.
Under Authentication, select Manage OAuth Client Access.
Enter the following information in the Manage API client access screen:
- In the Client Name field, enter the client ID from the Create Google Project and Service Account procedure.
- In the One or More API scopes field, enter https://mail.google.com/.
Click Authorize.