• an opt-out mechanism,
• a functioning return e-mail address,
• a valid subject line indicating it is an advertisement, and
• the legitimate physical address of the mailer.
• step-by-step junk mail filtering,
• protecting Sendmail, Postfix, qmail, Microsoft Exchange, and Lotus Domino servers from spam,
• McAfee SpamKiller for Lotus Domino and Microsoft Exchange,
• implementing and managing SpamAssassin, and
• antispam solutions for Outlook, Outlook Express, Mozilla Messenger, and Unix mail clients.