the toronto vegetarian association has some links to canadian stores both online and not online (some of the bigger vegetarian food stores in the toronto area have websites and may offer mail order), on its site: www.veg.ca
its a lot to wade through as the info is spread out in different sections, and you'd have to look at the external store links, but could be worth it if you find some stuff that you want there.

you might also find some stores both in your area, and/or that mail order across canada, by using happy cow... the canada search page is: http://www.happycow.net/north_america/canada/index.html

i also just found this store through google: www.eatit.ca its not solely vegan/vegetarian, but its organic, and if you are prepared to ignore the meat and just don't look in the meat and fish sections, it has lots of the general veggie stuff i see in the supermarkets here in ontario, like tofu, soy yogurts, beans, flours, herbs, nut butters, etc. i've not shopped online for food in canada, so i'm not sure whats excessive in terms of shipping (your postal system seems generally extortionate to me, compared to what i'm used to in england) but it could be worth a look.
hope some of this helps!