In the US, there's a wonderful service, more cost effective than the Post Office for almost all package-delivery applications. It's called UPS and referred to tersely and fondly as "UPS Ground". It's so addictive that given the similarity of addresses between the US and Canada for the post, US residents who have parcels to send to Canada naturally assume that Brown will get the job done.
Well, it will but... There's the little matter of a border between the two countries, and it happens that when you send things via Brown, your "gift" suddenly becomes a COD parcel, possibly challenging the value of the gift in the first place. The thought counts, and we Canadians are too polite to complain loudly to our generous friends, but seriously. For all the tackiness of "gift cards", suddenly a gift card at amazon.ca, for instance, makes a whole lot more sense.
Now, it used to be a whole lot worse. There used to be a several week delay while Brown tried to negotiate the border and send the package around in Canada using their then half-baked delivery network up here. They've gotten a lot better and are no longer a byword in bad delivery. But they are a bad deal, and if you're in the US, shipping to Canada, they're a bad deal that you probably won't hear about from your friends north of 49. We like you. The gifts you send are thoughtfully chosen and highly appropriate, 95 times out of 100. Why should we quibble about how you choose to send them to us? But there it is.
For sending parcels to Canada from the US, the post office is a better deal, if not for you, then certainly for the people you're sending to. And if their rates are just over the edge, maybe an over-the-web gift cetificate will work better. Last time I checked, those really were duty-free.