Definitions for "Junk e-mail"
Junk E-mail is similar to the mounds of junk-mail that plague residences accompanied by those annoying phone solicitations. The only distinct difference between the two is that you receive these ads via e-mail. These advertisements, however, are not free due to connection and storage costs they require. Cyber consumers can also have their mailboxes "bombed" by one of these ads, totally disabling their e-mail account.
unwanted e-mail (usually of a commercial nature sent out in bulk)
Unsolicited commercial e-mail; also known as "spam." Usually junk e-mail doesn't contain the recipient's address on the "To" line. Instead, the addressee is a made-up name, such as "[email protected]." Or the address on the "To" line is identical to the one on the "From' line.