Confirmed Opt In - A Rose by Any Name

This report explains Confirmed Opt-In (COI) / double opt-in best practices for bulk email lists, recommending verification of subscriber addresses to prevent forged or mistyped sign-ups, reduce spamtrap contamination, and provide an auditable trail for complaints. It references guidance from major providers (Yahoo, Google, Microsoft), ESPs and examples of organizations using COI, and notes related list-management techniques such as unsubscribe handling, bounce processing, and occasional "permission pass" cleanups.