Post office
United States Postal Service
6 locals recommend,
Location
526 W Fremont Ave
Sunnyvale, CA
Nimitz
Tips from locals
There is many other amenities nearby, hiking, parks, restaurants, services, festivals, & events. I made a guide booklet for the room with maps and things to do locally and further afoot.
There are the blue drop off boxes closer, but if you want to know where to closest post office is, this is it.