Simple Address check via API
There are several API services that allow bulk address queries. 

For example smartbit's API takes up to 1,000 addresses with their v1/blockchain/addresses endpoint which will return details about each address sorting by the highest balance first. 

Example GET request:
https://api.smartbit.com.au/v1/blockchain/addresses/1DuMuchPBGNoi5b9JmpreZ2L5EpuMiJdyc,1N75aWck3TFPorTvSgdzLUttY8uddqTAFZ,161UqtBktXJMzcg2zxBGMiHgnVrtH78Amx,19eK34996XoXPgpranrUVSPLmkxzowt8ox

Link to API docs: https://www.smartbit.com.au/api