Mailbox key not returned by the tenant

[Farnaz Z.]

Hello BP landlords,

My property’s mailbox keys were not returned by the previous tenants and my management company is saying that they can not get my mailbox keys until a new tenant is in the property so they can request a key with a copy of the lease. 
is there any way I can request a mailbox key from the USPS before my unit is rented?

I’m an out of state landlord so can not physically go to the USPS office.

Thank you for your guidance on this matter…

P.S. the USPS owns my mailbox 

[Nathan Gesner]

Quote from @Farnaz Z.:

I don't understand why that's a concern. The only mail that could possibly be delivered there is the mail belonging to the previous tenant. I know you don't want them using the box, but there's really no harm to you and it's only until a new tenant is placed, then USPS will change the locks.

However, you could let the post office know the unit is vacant and ask them to stop delivery to that address until a new tenant is placed. I don't know if that's possible, but it's worth trying if you are still concerned.