Cluster Mailbox - Can landlord use one of the boxes?

[Matt W.]

My multifamily property has cluster mailboxes.  Does anyone know whether I can, as the property owner, legally use one of the boxes as a business PO Box?  If permitted, I'd imagine I would need to work with USPS to create a "dummy" apartment number that would be recognized as my business mailing address for the property.  Does anyone know if USPS permits this?