Citibox Mayfair - the Mailbox Company. A FedEx Authorised Ship Centre Citibox Mayfair is located within London's most exclusive district, Mayfair is home to some of the finest shops, hotels and restaurants in the world, as well as being a highly prestigious business district. Our store is conveniently located in Lansdowne Row - one of the smartest addresses in the capital for your private correspondence or virtual office. For the right address in the right London location, choose a mailbox with Citibox Mayfair. It is like a PO Box service. Choose from Mailbox rental, Virtual office, Telephone answering. Rent a prestigious mailbox or virtual office address at Citibox Mayfair. We also offer a range of courier services and postal services.