CPC Mississauga can take up to 45 days to assess a sponsor, and then you have to allow another week or so for receipt of the decision letter. You will not receive confirmation of receipt of the application prior to receiving the decision letter. If it's a positive decision, CPC-M will then transfer the application to the overseas visa office. You will get a letter from them acknowledging receipt (AOR) and notifying you of your new file number. How much longer it takes from that point depends on the
processing timeline for your particular overseas office.