The consensus from experts, marketers, and documentation suggests that while DKIM configuration is a vital part of email authentication for Google Workspace and O365, it's not entirely sufficient on its own. For non-bulk mail, any DKIM might suffice, but alignment is preferable, while bulk mail necessitates alignment. Custom DKIM records specific to your domain are crucial for improved deliverability and proper authentication, overcoming limitations of default configurations. Integration with SPF and DMARC is essential for a robust defense against spoofing and phishing, with DMARC providing the policy framework for handling authentication failures. Proper DKIM setup involves generating keys, adding DNS records, and enabling signing, with Microsoft recommending two keys for redundancy. Failing to configure DKIM correctly can lead to emails being marked as spam.