The term MULE in relation to email refers to a separate account you maintain and is used when signing up for online offers or registering with a site which requires your email address. Using a MULE email account helps to reduce Spam
Cagebird breeders sometimes use the word mule for hybrids bred in captivity between species of finch, such as goldfinch x canary.
Modern usage may designate as a mule someone who, knowingly or unknowingly smuggles something onto an airplane or across a national border, sometimes aware that they are smuggling, but not knowing what is in what he or she smuggles. For example, a terrorist may tell someone that a package contains diamonds and persuade him or her to smuggle it; however, the package actually contains a bomb. Anyone transporting drugs might be referred to as a drug mule, a topic at the center of the 2004 film Maria Full of Grace.
In video games, and in particular in MMORPGs, a mule is a subsidiary character used as a beast of burden. See multi.
M.U.L.E., a multiplayer video game written in 1983
There was an early cotton spinning machine called Crompton's mule.
