Fridge water "overflow" ?

Question

A plastic 'gutter / water collector' is mounted inside on the back (under the cooling element) with the water outlet drain in it's centre which apparently goes into the back of the fridge.Where does this water-outlet go to ? It seems this outlet is 'blocked' because between cooling cylces it overflows and accumalates in the bottom of the fridge.There is NO outlet outside at the back of the fridge whatsoever or anywhere else to be seen.