Customers who send bulk email must have a method of confirmation or verification of ,subscriptions ("Subscription Confirmation") and must be able to show evidence of such Subscription Confirmation to users ,who complain about receiving unsolicited email. Customer shall keep all Subscription Confirmations for each mailing list ,address for the duration of the existence and use of any mailing list and for a reasonable time after such use. Customer ,must provide a mechanism by which email recipients can submit requests to unsubscribe from any mailing list. Customer ,must honor all unsubscribe requests within 5 business days.