If you don't use MMT much, then close the MMT one, generally speaking, Coral is less bad than the other one... However, if you use MMT for travel bookings, then it makes sense to keep it.
But again, if you use MMT, don't stick to using it. There is a plethora of Travel agencies for booking with lesser convenient fees, like Kayak, Agoda, Gotogate, via, etc etc. So, that is also something to consider.