CAN-SPAM Act - a law that sets the rules for commercial email, establishes requirements for commercial messages, gives recipients the right to have you stop emailing them, and spells out tough penalties for violations.
Unsolicited Commercial Email Legislation - State Laws Relating to Unsolicited Commercial or Bulk E-mail (SPAM)
Coalition Against Unwanted Commercial E-Mail - CAUCE provides information and resources for defending the interests all users in the areas of privacy and abuse in all its forms on the Internet.
Direct Marketing Association Telephone, Mail & E-Mail Preference Services - opt out of unwanted marketing email
National Do-Not-Call Registry - Add your telephone numbers to the "do not call" list to avoid unwanted marketing cold-calls