Citibox Kensington - the Mailbox Company. A FedEx Authorised Ship Centre. South Kensington is one of London's smartest districts. Our store is right at the centre of it all, on the famous Old Brompton Road - the perfect address for your private correspondence or virtual office. For the right address in the right London location, choose a mailbox with Citibox Kensington. It's like a PO Box address. Choose from Mailbox rental, Virtual office, Telephone answering. Rent a prestigious mailbox or virtual office address at Citibox Kensington. We also offer a range of courier services and postal services.