This question already has an answer here:
I am going back from 14 days US vacation to Germany via Denmark, flying on Air Canada from Newark, transferring in Toronto and leaving Toronto to Copenhagen (CPH) on Air Canada 4 hours later. Both AC flights are on the same ticket and I am German. On a separate Star Alliance ticket (Scandinavian Airlines), I will fly from CPH to Germany after 2 hours layover in CPH.
Will I be able to check my luggage through to Denmark or Germany from New York? Don't think so, because from Toronto Airport Website I understood, that I will have to gather and recheck my luggage.
I have read on a forum, that at Toronto Terminal I might get "locked" in an area, from where it is impossible to go to the Maple Leaf Lounge until it is time to go to customs and security. Did I misunderstand or might something similar be possible?