Be careful though. The whole "got it as a gift from x and y" is such a typical excuse to sell off knockoffs, fakes and stolen stuff. If something is brand new in box, the chances of a scam goes up a million fold. Your best bet is punching in the serial number into the warranty thing but even that doesn't guarantee anything as it could just be a copy of a valid serial.
Also depends on where you live too.
EDIT: just want to add that this is more of a general precaution and not necessarily aimed at the OP as their experience seemed to have went OK