From RCMP's Website
http://www.rcmp-grc.gc.ca/cfp-pcaf/faq/trans-eng.htm
Transporting Firearms
Frequently Asked Questions
* Do I need authorization to transport my firearms from one location to another?
* How do I obtain an authorization to transport a restricted or prohibited firearm?
* Can I send firearms in the mail?
Q. Do I need authorization to transport my firearms from one location to another?
Any time you personally transport a restricted or prohibited firearm within Canada, you need an Authorization to Transport (ATT) from the Chief Firearms Officer of the province where the firearm is located or where it will be entering Canada.
You do not need an ATT for firearms that are being shipped by licensed carrier or for non-restricted firearms that you are transporting yourself.
Q. How do I obtain an authorization to transport a restricted or prohibited firearm?
If you have a valid Canadian firearms licence authorizing you to possess that class of firearm, you can apply by calling 1 800 731-4000 or by submitting form CAFC 679 to the Chief Firearms Officer (CFO) of the province or territory where the firearm is located.
If you are a non-resident and are using a Non-Resident Firearm Declaration to bring a restricted firearm to Canada for an approved purpose such as target shooting, you will need to apply for an ATT by phone when you reach your point of entry. All of the CFO offices can generally be accessed from 9.a.m. to 4:30 p.m., Monday to Friday, in all Canadian time zones, by calling 1 800 731-4000 (Canada and the U.S.) or 1 506 624-5380 (outside Canada and the U.S.) Keep these hours in mind when making your travel arrangements.
If you will be arriving outside of the CFO’s regular weekday office hours, you may wish to contact the applicable CFO in advance to see if you can make other arrangements for obtaining an ATT.
Q. Can I send firearms in the mail?
You may ship restricted firearms, non-restricted firearms and prohibited handguns from one Canadian location to another Canadian location if you use the most secure method offered by Canada Post that requires a signature upon delivery. Prohibited firearms, other than prohibited handguns, and firearms being shipped across the Canadian border, must be shipped by an individual or carrier company licensed under the Firearms Act to transport those classes of firearms.
You are required by law to ship firearms unloaded and in a safe and secure manner to deter loss, theft and accidents.
IMO if you receive the parcel at the door you don't need any ATT, but if you have to physically go down to the post office to pick it up, then you would need a ATT valid from the post office to your home as YOU will be transporting a restricted firearm.
But then again, I could be wrong.