The specs of Motorola Moto E (XT1022) at Motorola’s website (and GSMArena) state that it supports a maximum of 32 GB of expandable storage. But the reality goes beyond as the Moto E loaded up a 64 GB SD card very well. This brings it at par with majority of the mid to high end smartphones from other manufacturers.
The phone comes with 4GB of internal storage and a MicroSD card can push it to around 60 GB or higher (a 128GB Card was not tried). But the internal storage might still be a limiting factor as Apps and Games cannot be installed on the MicroSD card. This may be overcome through rooting the phone, but out of the box, Moto E has only around 2 GB of free storage to install apps and games.