You arrive at a delivery address and find the correct mailbox but notice the house appears unoccupied (uncollected mail, newspapers piling up, no signs of recent activity). A certified mail piece requires a recipient signature. What is the CORRECT action?

CERTIFIED MAIL requires a signature to complete delivery — this is the defining characteristic and purpose of certified mail service. The sender is paying for delivery confirmation and recipient acknowledgment. CORRECT PROCEDURE FOR UNSUCCESSFUL CERTIFIED DELIVERY: (1) MAKE DELIVERY ATTEMPT: knock on door; ring bell; check for any occupant; (2) IF NO ANSWER: leave a DELIVERY NOTICE (PS Form 3849) in or on the mailbox; the notice specifies: the item type; date of attempt; how many attempts remain; how the recipient can claim the mail (redelivery request or pickup at the post office); (3) RETURN CERTIFIED MAIL to the carrier's vehicle; bring back to the station; input the attempt into the tracking system; (4) SUBSEQUENT ATTEMPTS: USPS policy allows a set number of attempts (typically up to 3 business days, or per customer request) before the item is held at the post office for pickup; (5) IF UNCLAIMED: after the hold period, certified mail is returned to sender as 'unclaimed.' REGARDING THE 'UNOCCUPIED' OBSERVATION: this is NOT the carrier's role to investigate or determine; accumulation of mail and newspapers may indicate absence, illness, or other circumstances; mail should continue to be delivered and delivery notices left per protocol; if genuinely concerned about a resident's welfare, a carrier can mention the observation to their supervisor; FEDERAL LAW: mail carriers cannot open, read, or withhold mail without authorization — doing so is a federal crime. IMPORTANT: the observation about accumulated mail is irrelevant to the proper certified mail procedure — follow protocol regardless.