Is it OK to Move a Mailbox?
The USPS provides specific guidelines for a home's mailbox location. If a homeowner needed to move their mailbox to a different location, because of road or driveway construction as an example, and it would be a unique or custom design, it would be a good idea to check with your local postmaster. In most cases moving a mailbox should not be a problem as long as the general guidelines are followed. It needs to be visible and have easy access from inside a postal vehicle, mailboxes must be placed where the driver can conveniently and safely serve them without leaving his or her vehicle, they must be on the right-hand side of the road in the direction of the route line. The Postal Service does not regulate mailbox supports/posts in any way except for the purposes of carrier safety and delivery efficiency. Homeowners are responsible for ensuring that posts are neat and adequate in strength and size.
In addition, the Federal Highway Administration (FHWA) has determined that wooden mailbox supports no larger than 4-by 4-inches, or a 2-inch diameter standard steel or aluminum pipe, buried no more than 24 inches, should safely break away if struck by a vehicle. According to FHWA, customers must also securely attach the mailbox to its post to prevent separation, if struck.
The best answer would be to call or write a letter to your local postmaster making your request, and far more importantly the reasons why. It may be beneficial to wait until you hear an answer, confirming it will be approved long as you follow all other rules and regulations that are recommended.
The postal system has set routes, some are driven, some walked. Moving a mailbox may result in your mail going missing/undelivered. It is also important to make sure you are not part of a grouping (HOA, apartments, broken parcel of land) and that additional approval outside the USPS must be received.