DKIM (DomainKeys Identified Mail) ensures message integrity by using digital signatures to verify that an email message has not been altered or tampered with during transit. When an email is sent, the sender’s domain adds a digital signature to the message header, which includes a hash of the message content, as well as information about the sender’s domain and public key.
When the message reaches the recipient’s domain, the DKIM signature is verified using the sender’s domain’s public key. If the signature is valid, the recipient can be sure that the message has not been tampered with and that the sender is who they claim to be. If the signature is invalid, the message may be rejected or flagged as suspicious.
Overall, DKIM provides a way to validate the authenticity and integrity of email messages, thereby helping to reduce the likelihood of email fraud, phishing, and other malicious activities.
