1. Person indicates his desire to sign up for an e-mail subscription on a site. 2. The site sends a confirmation e-mail to the subscriber. 3. The subscriber must respond as directed in the e-mail for the subscription to be valid.
If the subscriber does not respond to the confirmation e-mail, the subscription is canceled. This sign-up process is considered by e-mail marketing experts to be the best process to ensure only people who really want to be on a list are added to it.