I was all set to hit SEND on my answer when I realized you can't put Canadian postage on your return envelope obviously. (A mistake I see Daniel made as well
)
So I did a little searchin' for ya, because I am just that helpful... and just that bored. Ok, apparently you can purchase an IRC (International Reply Coupon) from Canada Post at any Canadian postal outlet, at a cost of $3.95. Ask them to weigh your magazine(s) and they should be able to tell you how many IRC's you're going to need. Then just put them on your SASE, and you should be good to go.
I remember doing this for stuff I sent to England years ago, and the IRC's really do work. So hope that helps you.
I am obsolete. This must be what old people feel like. And Blockbuster.
- Dollhouse (R.I.P.)