The comprehensive feedback from experts, marketers, and documentation sources strongly advises against implementing DomainKeys. DomainKeys is considered obsolete, superseded by DKIM (DomainKeys Identified Mail), and not a relevant email authentication method for modern email systems. While technical resources for DomainKeys implementation exist, the consensus is to focus on DKIM, SPF, and DMARC to improve deliverability, prevent spoofing, and protect brand reputation. Major email providers do not check for DomainKeys, and it's not integrated with DMARC. Therefore, implementing DomainKeys is not worth the effort.