The commentary to 1005.17(b)(1)(iv) states that you can either provide a copy of the model A-9 form to the consumer or mail the consumer a notice. Only one is required so you are doing more than is expected. However, keep in mind that opt-ins can be accepted over the phone or via email. If the customer is not present in person to receive a copy of their opt-in decision and you have suspended the mailing your system generates the following day, you would be out of compliance with this section.
"Confirmation. A financial institution may comply with the requirement in § 1005.17(b)(1)(iv) to provide confirmation of the consumer's affirmative consent by mailing or delivering to the consumer a copy of the consumer's completed opt-in notice, or by mailing or delivering a letter or notice to the consumer acknowledging that the consumer has elected to opt into the institution's service. The confirmation, which must be provided in writing, or electronically if the consumer agrees, must include a statement informing the consumer of the right to revoke the opt-in at any time. See § 1005.17(d)(6), which permits institutions to include the revocation statement on the initial opt-in notice. An institution complies with the confirmation requirement if it has adopted reasonable procedures designed to ensure that overdraft fees are assessed only in connection with transactions paid after the confirmation has been mailed or delivered to the consumer."