Federal law and policy is dicated by the Parliament of Canada. Members are elected officials known as Members of Parliament (MP). No postage (stamp) is required to send a letter to your MP. There is a section on the Parliament homepage to find your MP by post code.
Provincial laws are controlled by the individual provincial/territorial parliaments. Members are elected officials. In Ontario, members are known as Members of Provincial Parliament (MPP). In Newfoundland and Labrador, they are called Members of House of Assembly (MHA). And in Quebec, they are referred to as Members of National Assembly (MNA). Everywhere else in Canada, they are known as Members of Legislative Assembly (MLA).