Depending on your energy level and the circumstances, you might want to continue pursuing the issue, if for nothing else than to have them revisit their policies and be more forthcoming.

Their recent information is pretty clear that packages cannot be left at the door unless it is out of plain view from passersby. Do you have an enclosed porch or screen door behind which the package was left ?

Here is a link to read more. Good luck.

http://www.canadapost.ca/cpo/mc/personal/support/helpcentre/tracking/safe_drop.jsf

Although the horse has already left the barn in this particular instance, you can help to avoid this situation in the future by asking the sender to write in big A$$ letters, "do not safe drop". Then if it is safe dropped, you have a little more leverage.

Could also go further and have a sign of some kind on your porch asking that no packages be left. Might be a little tacky, but you could put the sign out only when expecting a package, eh.