ESIGN has no requirements regarding the use of electronic signatures. It simply says "they're legal." Its only requirements relate to the (optional) use of electronic documents for delivering information to consumers. If you're sending some type of information to a consumer because a federal law/regulation (1) requires you to deliver the information, and (2) that law/reg requires you to deliver the information "in writing", and (3) the consumer agrees to receive the information electronically (instead of receiving it in paper form), THEN you and the consumer must engage in the prescribed (by ESIGN) informed-demonstrable-consent "handshake." That's it. Any other requirements come from sources other than ESIGN.
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...gone fishing.