Went ahead as I was planning and surveyed the location of all community mailboxes, which simultaneously act as letter- and postboxes. I have the locations for (AFAIK) all of those west of Fréchette Street (north of Fauna Street) and Lapierre Street (south of Fauna Street, but not farther south than the Françoise Giffard Street intersection). I also mapped in a very rough fashion the unmapped street segments located north of the Grey Pines and Alliance Street intersection. Ironically enough, I came across a postal employee busy at this one right as I was finishing my run.

As a side note, it was a nice occasion of surveying some of the nice architecture in the area. Spotted some old houses, but also was dismayed at the overwhelming march of vinyl, which is replacing the older-style wooden sidings and destroying much of the personality of many buildings. I was also suprised to find out the northern segment of Fréchette Street is entirely devoid of boxes, as appears to be Lapierre and Fauna streets. I wonder if they are serviced by the boxes on adjacent streets or at the post office...

I'll also have a try at using the Canada Post address-to-postal code widget to see if I can match the boxes to specific LDUs within the G3E FSA that covers Saint-Émile, though I'm doubtful as to the chances of success...