A mailbox or also referred as letterbox is a receptacle intended for receiving and containing mails. There are different designs for mailboxes such as: a wall slot type, door slot type, pre-designed box attached or mounted to the house or outside near the street, and a centralized type consisting of individual mailboxes put in one big unit intended to cater several households or neighborhood.
Some people might not mind having their own mailbox and would choose PO box instead. It doesn't matter which one is preferred because it serves the same purpose. PO boxes are ideal for those who only rent certain spaces and prefer to have a more private mail delivery system though as compared to classic mailboxes, the accessibility and convenience of having it right where you live isn't met by PO boxes.
Some people on the other hand give much importance with their mail delivery system. Homeowners mostly get their specially designed Gaines mailboxes or Keystone mailboxes to add some classic charm to their home. Having better mailboxes also benefits the homeowner because it offers better security for their mails. Some mailboxes have locks which obviously secures important mails from some stranger's prying eyes.