Where in New York is post office open on Sunday?

In New York City, several post office locations are open on Sundays, particularly those that provide package services. Notably, the main post office at 421 E 151st Street in the Bronx and the one at 320 W 34th Street in Manhattan offer Sunday hours. It's advisable to check the USPS website or contact the specific location for current hours and services, as these can vary.