The best way to get rid of junk mail is to have the recipient's name and mailing address removed from mailing lists. This generally involves contacting the companies that send junk mail and ask to be removed from the list.
Most junk mailings offer some sort of contact information, whether an email address, telephone number or mailing address. Those concerned with receiving junk mail should contact the company and ask to be removed. Since all mailings cost the company money, most prefer to remove unwilling recipients rather than continue to waste money mailing junk advertisements to those who have no interest in receiving them.