If you are shopping here on dotCA (and not the US site dotCOM) all the sellers are required to ship to Canada.
Some sellers use couriers for shipping, and couriers cannot deliver to PO boxes.
If the seller does use couriers, be aware that the courier will not only charge import fees (duty over $150 and taxes over $40) but will also charge a steep "customs brokerage" fee.
This does not apply to US sellers using the eBay International Shipping program.
With eIS you will be paying any applicable import fees before the seller ships.
