jingle mail
n.— «In the great Southern California bust of the early 1990s, real estate legend holds, many defaulting homeowners mailed their keys back to the lenders, in effect washing their hands of the whole matter, and promptly left town. Thus was born the term “jingle mail.”» —“Mortgage spike forcing evictions in the nice neighborhoods, too” in California Charleston Daily Mail (Charleston, West Virginia) May 6, 2007. (source: Double-Tongued Dictionary)