SDCL § 37-24-47: Prohibited commercial e-mail advertisements.

No person may advertise in a commercial e-mail advertisement either sent from South Dakota or sent to a South Dakota electronic mail address under any of the following circumstances:

(1) The e-mail advertisement contains or is accompanied by a third-party's domain name without the permission of the third party;

(2) The e-mail advertisement contains or is accompanied by falsified, misrepresented, or forged header information;

(3) The e-mail advertisement has a subject line that a person knows would be likely to mislead a recipient, acting reasonably under the circumstances, about a material fact regarding the contents or subject matter of the message.