MailSword

For every email received from an unknown sender MailSword automatically verifies whether the sender is in fact human by asking the sender to type a 4-digit passcode. All legitimate unknown senders are able to easily confirm their email. The spam will never find a way to your mailbox because spammers are either using fake return email addresses or using automated mass mailing scripts incapable of responding in human fashion. Correct passcode needs to be typed only once and only by the unknown sender. MailSword automatically imports all existing "email friends" from the popular email clients. MailSword supports multiple e-mail accounts and all popular e-mail clients.

Requirements:

Windows 95/98/Me/NT/2000/XP