Eto po ung tinatawag nila na Sponsor's Approval Letter (via e-Mail).
You don't have to do something unless there are necessary changes po.
You must notify Citizenship and Immigration Canada (CIC) of any changes to your application. Examples of changes include:
-Changes in your personal circumstances, such as birth or adoption of a child, death of a family member, a marriage or a divorce;
-Change of contact information (e-mail, mailing address, telephone number);
-Appointment or change of immigration representative or designated individual;
-Decision to withdraw your application.
If you have no changes to make, just wait for the PPR = Passport Request, which is probably via e-Mail also, based on my experience po.
Hope these info will help you.
Have a nice day po!