Hello,
Based on my experience, you receive two CSQ copies by mail. At the bottom of the page, one has "immigration" written on it. Scan that document and send it via webmail to IRCC. Most of the times MIFI sends it automatically, but just to be safe send it as well. Moreover, you only get an automated response from IRCC that your email has been received and that if you have sent any documents by webmail, they will be added shortly.
If you have the new PR tracker tool, you will see an update there that "WE HAVE RECEIVED YOUR ENQUIRY", that means that they have received your CSQ.