fright mailnoun.
Letters and other mail pieces that use scare tactics to solicit money.
Example Citation:
"One grisly category of the junk-mail problem is the targeting of vulnerable senior citizens for scary demands that they send money or risk dire consequences....This 'fright mail,' using sucker lists of people tabbed as easy touches for having contributed before, is depressingly effective in moving the susceptible to contribute."
Editorial Staff, "Postal assault on old folks," The San Francisco Examiner