It is a common courtesy to not block mail boxes.According to the U. S. Postal Operations Manual, if a mailbox istemporarily blocked, "the carrier normally dismounts to makedelivery". If the mailbox continue to be blocked, the Post Mastermay withdraw delivery service - but that requiresnotifications.The customer has to have the ability to control access to themailbox. If someone is constantly blocking access to your mailboxso you no longer get mail, that might be resolved by looking atlocal ordinances. Some communities might have regulations regardingthat - including parking too close to a driveway, etc.