Royal Mail said it has a legal duty to remove postboxes on private property when asked to do so.
An Ipswich postbox that "vanished overnight" was removed after an official request.
Users of the Tuddenham Avenue postbox reported it had "vanished without notice or warning".
Royal Mail removed the postbox following a request from a property owner as it sat within the property line of a home on Tuddenham Avenue.
A Royal Mail spokesman said: "We are legally obliged to remove boxes on private property if we are requested to do so.
"We apologise to customers for the inconvenience and ask customers to use any other postboxes in the area or drop off mail at the local post office branch."
