The Melissa worm, also known as "Mailissa", "Simpsons", "Kwyjibo", or "Kwejeebo", is a mass-mailing macro virus, hence leading some to classify it as a computer worm. First found on March 26, 1999, Melissa shut down Internet mail systems that got clogged with infected e-mails propagating from the worm. Melissa was not originally designed for harm, but it overflowed servers and caused unplanned problems.