I originally intended to rent a mailbox from the post office to receive QSL cards, but the local post office no longer offers this service. That is, a mailbox that is physically located inside the post office (P.O. Box), which I learned online that some regions still offer this service, but it's very rare. Currently, mailbox rental services are more mature in other countries, while in China, they have almost disappeared. After that, I purchased a stylish metal postal mailbox and hung it downstairs. Then, after communicating with the postal delivery personnel, the mail was delivered to this location. Currently, receiving mail is normal, but sending mail requires going to the post office. This is for reference.