Early Joe jobs aimed at tarnishing the reputation of the apparent sender or inducing the recipients to take action against them (see also email spoofing), but they are now typically used by commercial spammers to conceal the true origin of their messages and to trick recipients into opening emails apparently coming from a trusted source.
Besides prompting angry replies, it also caused joes.com to fall prey to denial-of-service attacks, from anti-spam vigilantes who thought he had sent the mail, which temporarily took the site down.
[2] Some e-mail Joe jobs are acts of revenge like the original, whether by individuals or by organizations that also use spam for other purposes.
Joe-jobbers could also be businesses trying to defame a competitor or a spammer trying to harm the reputation of an anti-spam group or filtering service.
Some joe job attacks adopt deliberately inflammatory viewpoints, intending to deceive the recipient into believing they were sent by the victim.
False headers are used by many viruses or spambots today, and are selected in a random or automated way, so it is possible for someone to be joe jobbed without any human intent or intervention.