Enabling DMARC can help improve a domain's email reputation and deliverability by:

• Requesting feedback from ISPs: By publishing a DMARC record, the domain owner requests ISPs (who support DMARC) to send feedback on the messages that they receive for that domain. This alerts receivers that an organization wants to improve its email authentication.
• Providing valuable insights: When a DMARC record is published, valued DMARC reports that give insight into the email channel are received. The DMARC reports show which sources and IPs send out messages on behalf of a domain. It also provides additional results of the SPF and DKIM verification.
• Improving email authentication: Once these results have been reviewed, the domain owner can improve the SPF and DKIM verification of these messages. These steps increase the trustworthiness of a domain and can lead to ISPs being more willing to place messages in the primary inbox of the receiver.
• Mitigating malicious messages: When SPF and DKIM are set up correctly, a domain owner can start with enforcing a DMARC policy. Enforcing the DMARC policy mitigates the impact of malicious messages that are sent on behalf of the domain, thereby preventing spoofing.
• Guaranteeing email security: This shows ISPs that a domain owner guarantees the security of the email channel and receivers can trust the messages originating from the domain.
• Increasing trustworthiness: These steps increase the trustworthiness of a domain and can lead to ISPs being more willing to place messages in the primary inbox of the receiver. This has the effect of improving email deliverability.

In summary, DMARC is an email authentication system that protects domains from email spoofing, phishing scams, and other cybercrimes. The benefits of using DMARC include leveraging existing email authentication techniques, adding a vital reporting function, and protecting domains against phishing or spoofing attacks. DMARC can also significantly improve a domain's email deliverability and reputation by publishing a DMARC record, using DMARC results to improve authentication results, and enforcing the DMARC policy. These steps increase the trustworthiness of a domain and lead to ISPs being more willing to place messages in the primary inbox of the receiver, thereby improving email deliverability and the domain's reputation.