Hi, where are they coming from? nobody knows - all over the net. Can you stop them, probably not, but your email program may have a Junk folder to where than can be directed, rather than your In folder.
Dunno what email program you are using, but I would recommend click here (free) and complete with automatic Junk/Unapproved Folder which is automatically emptied when you close Incredimail after use. I would not contemplate ever using any other email program.