you can drop off your usps shipment at one of the over 34,000 post office locations within the united states. Alternatively, drop off your usps shipment at one of. a map to find the nearest blue usps mailbox locations with pickup and collection times near me. Look up a zip code ™ hold mail. Rent/renew a po box. this page lists locations of usps collection stations (blue mailboxes) and post offices in riverside, california. Click on the address to see important details, including a map of. Search for nearby post…