What is the purpose of Domain Keys Identified Mail (DKIM)?

The purpose of Domain Keys Identified Mail (DKIM) is to serve as a security protocol designed to detect email spoofing. DKIM helps ensure that an email was indeed sent from the domain it claims to be from, thus providing a way to validate the authenticity of the email source. By adding a digital signature to the headers of an email, DKIM allows the receiving mail server to verify that the email has not been altered in transit and confirms the sender's domain.

This security measure is crucial in combating phishing attacks and ensuring that only legitimate communications are delivered to recipients' inboxes. In doing so, DKIM enhances trust in email communications and reduces the chances of fraudulent activities associated with email spoofing.

The other choices do not accurately reflect the primary function of DKIM. Tracking email open rates is not a function of DKIM; rather, it relates to email analytics. Measuring email engagement also does not pertain to DKIM's responsibilities and focuses instead on understanding how recipients interact with email campaigns. Lastly, segmenting email lists based on interests is a marketing strategy that involves categorizing contacts to better tailor communications and lacks any relation to the security functions offered by DKIM.