I plan on flying from the US to Europe (Schengen) through Montreal airport (Trudeau Airport, YUL). The flights US-Montreal and Montreal-Europe are two different bookings. For the sake of simplicity, let's say I do not have any checked-in luggage.
According to the website of the airport, if I connect from USA towards a non-US international destination with automatic luggage transfer (or no checked-in luggage), I have to "go to the special international connections customs counter". But does that involve only customs or also immigration? I am particularly interested in knowing if my passport will be checked, if that makes sense.
So, do I have to go through some form of immigration/passport check when connecting in Montreal from the US to Europe?