Emirates has the following to say about this, on their website:
If your journey includes any destinations in Canada, North America or
South America, different baggage rules apply.
The total dimensions (length + width + height) of each piece must not
exceed 150cm (59 inches). You’ll be charged an additional fee for any
individual items exceeding dimensions of 150cm (59 inches), up to a
maximum of 300cm (118 inches). If an individual item has total
dimensions greater than 300cm (118 inches), it can’t be checked in as
baggage and will need to be sent as cargo or freight.
If you check in two pieces of luggage (in any of our three classes),
the total combined dimensions of both pieces should not exceed 300cm
For travel to and from Canada and North America, you can check in two
bags of up to 23kg each in Economy Class, and two bags of up to 32kg
each in First Class or Business Class.
Therefore, in your case you bag will be accepted, but you'll be charged a fee as it exceeds the dimensions.
Emirates provides a baggage fee calculator, but this only allows you to purchase extra baggage at a discount. It does not display rates for oversize baggage:
**The checked baggage allowance and excess baggage rates calculator is for your information only. Overweight and oversize charges might
apply. Please contact your local Emirates office for more information.