The location for storing unwanted e-mail as determined by a spam filter. Also called a "junk folder" or "junk mailbox," spam folders are created by mail servers as well as by the user's e-mail program. In some mail programs, the messages in the spam folder can be sorted and viewed by the spam filter's rating, which is a percentage of confidence that the message is junk. Messages with lower ratings, such as below 50%, can be reviewed more carefully to be sure they are not legitimate. See spam filter.