Mailable adj. Admissible lawfully into the mail. Opposed to non-mailable. Dangerous items such as explosives, weapons, or corrosive chemicals are often classified by the postal authorities as non-mailable. (U.S.)
... arrival of the first of the American steamers bound to Bremen at Southampton, in the month of June last, the British post-office directed the collection of discriminating postages on all letters and other mailable matter which she took out to Great Britain or which went into the British post-office on their way to France and other parts of Europe. The effect of the order of the British post-office is to subject all letters and other matter transported by American steamers to ... — A Compilation of the Messages and Papers of the Presidents: Polk - Section 3 (of 3) of Volume 4: James Knox Polk • Compiled by James D. Richardson
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