Guys..crazy experience..
Im inland mpnp april 24, 2015. Got ppr on 5th april, sent passport same day. On april 11 my return tracker was activated from Ottawa. I live in Winnipeg and myself filled in my address on returning envelope. However on april 12 it was out for delivery in Montreal. So weird and I was shocked.. anyways Canada Post told me address is for Montreal and I should contact Ottawa, they returned the envelope to the sender in Ottawa. I freaked out as it had my passport and possibly COPR. Today I got a email from Ottawa admitting their mistake, which I appreciate, they will send it back to me via xpresspost and gave me a new tracking number. Close call, had I not tracked returning envelope it would have been delivered in Montreal somewhere.
Guys always ask for signature on both sending and returning envelope.I did not ask signature on returning one, maybe thats they put someone else's label on my envelope and send to Montreal. Good luck!!