There is a drain for defrosted water inside the freezer, under the evaporator coils. This drain is definitely plugged and frozen.
Remove the freezer drawer as described in the User manual
(page 8). Using a hair dryer defrost the ice on the bottom and the drain hole under the evaporator. Blow some air through the drain and run hot water to confirm it is open.
Here are the breakdown diagrams and Replacement parts for Maytag MFF2558VEM4 REFRIGERATOR | AppliancePartsPros.com