No you can apply at a post office but then you need to send the orginal copies of your identification if you go to the harry hayes or the south office they will just photo copy and check you identification so you dont have to send it in. But they don't provide pick up at the south location they would either mail it to you or you could pick it up at hary hayes. If you pick it up at harry hayes you wont have to wait in the huge line they have a seperate place to just come and pick it up and its takes no time usally.
This link might help.
http://www.ppt.gc.ca/can/offices.asp...C=on&chkSCC=on