usps

Learn what USPS Certified Mail includes, how much it costs, the delivery timeline to expect, and when it makes sense over regular mail.

Review the USPS rules on prohibited, restricted, and perishable items so you can avoid rejected mail or compliance problems.

Find the easiest drop-off locations, package rules to watch for, and what to bring so the shipment is accepted the first time.

Get a direct answer, the rule or process that applies, and the key exceptions, fees, or timelines to know before you act.

Check typical weekday and weekend delivery windows, cutoff times, and the factors that make shipments arrive earlier or later.