junk mail

plural junk mails · alternative junkmail

1. countableuncountablepostalAny mail or letters that are not welcome or solicited and typically sent in bulk; especially mail of a commercial nature such as advertising circulars and form letters.

   I don't believe it. Junk mail that talks back.

   1988 December 14, Stephen Wyatt, “The Greatest Show in the Galaxy Part 1”, in Doctor Who, spoken by Dorothy ("Ace") McShane (Sophie Aldred)

   1 more example

   In America alone, people spent $170 billion on “direct marketing”—junk mail of both the physical and electronic varieties—last year. Yet of those who received unsolicited adverts through the post, only 3% bought anything as a result.

   2013 May 25, “No hiding place”, in The Economist, volume 407, number 8837, page 74