What is another word for dead mail?
Pronunciation: [dˈɛd mˈe͡ɪl] (IPA) 
Dead mail refers to undelivered letters or packages that are unable to reach their intended recipients. Synonyms for dead mail include lost mail, undeliverable mail, returned mail, and unclaimed mail. Lost mail refers to items that have gone missing in the postal system and cannot be located. Undeliverable mail is addressed incorrectly, and cannot be processed by postal staff. Returned mail is sent back to the sender due to an incomplete or incorrect address. Unclaimed mail is delivered to the recipient's address but remains unclaimed for a period of time. These synonyms are used interchangeably to describe mail that is unable to reach its final destination.
