17 CFR §162.8

1. (a)In general. The opt-out notice must be provided so that each consumer can reasonably be expected to receive actual notice.
2. (b)Electronic notices. For opt-out notices provided electronically, the notice may be provided in compliance with either the electronic disclosure provisions in § 1.4 of this title or the provisions in section 101 of the Electronic Signatures in Global and National Commerce Act, 15 U.S.C. 7001 et seq.