Learner's definition of SOLE. always used before a noun. 1. : only or single. He became the sole heir to the property. the sole owner. The sole aim/objective/purpose of the program is to help the poor. She was the sole survivor of the tragedy. Icy roads were the sole cause of the accident. [+] more examples [-] hide examples [+] Example sentences [-] Hide examples
Dead letter mail or undeliverable mail is mail that cannot be delivered to the addressee or returned to the sender.ith increased collection and study of the postal markings originating from such offices, the body of literature on this obscure topic may grow. Many countries, including Canada and the United States, have issued special labels for envelopes that have travelled through the dead letter office.
According to the United States Postal Inspection Service, mail tampering is any obstruction that potentially prevents the legal pick up and delivery of mail by a postal worker. This includes damage to or destruction of a mailbox, delivering mail or other items to a mailbox through any means other than the postal service, mail fraud, mail theft or submitting a false change of address to the postal service.