unmailable

unmailable

A postal worker sets aside an unmailable package.

Definition

Adjective: "Unmailable" describes something that cannot be sent by mail, typically because it violates postal regulations (e.g., size, weight, content, or safety restrictions), or is otherwise unsuitable for mailing.

Usage Examples
  • (The package could not be sent by mail due to its contents.)
  • (The item was rejected for mailing because of its shape.)
  • (Such letters cannot be processed for delivery.)
Advanced Usage
  • "Unmailable matter": a legal or technical term referring to any item that postal authorities refuse to transport.
    • The post office classified the hazardous chemical as unmailable matter. (The substance was banned from being sent through the mail.)
Variants and Related Words
  • Mailable (adj): capable of being sent by mail.
    • This small box is mailable as long as it weighs under one kilogram. (It can be sent by mail.)
  • Unmailability (n): the quality or state of being unmailable.
    • The unmailability of the item was due to its flammable nature. (The reason it could not be mailed.)
Synonyms
  • Nonmailable: not suitable for mailing (synonymous with unmailable).
    • The liquid is nonmailable under current regulations. (It cannot be sent by mail.)
  • Undeliverable: unable to be delivered (often used for addresses, but also for items).
    • The address was incorrect, making the letter undeliverable. (It could not be delivered.)
Related Idioms (Indirect)
  • "Return to sender": a phrase used when an item is unmailable or undeliverable.
    • The letter was marked "return to sender" because it was unmailable. (It was sent back due to postal restrictions.)
Notes
  • This word is primarily used in formal or postal contexts. It is rarely used in everyday conversation unless discussing specific postal rules.