It works by adding a digital signature to outgoing emails, which can be verified by the recipient's email server using cryptographic methods. The sending mail server digitally signs the message using a private key. This signature includes a cryptographic hash of various parts of the email, such as the message body and headers, ensuring that the message has not been altered in transit and originates from a legitimate sender. The sending domain publishes a DKIM DNS record containing a public key that corresponds to the private key used for signing. This record is used by receiving mail servers to verify the authenticity of the DKIM signature.
One of the key benefits of DKIM is its ability to prevent email tampering and forgery. By digitally signing outgoing emails, DKIM provides a mechanism for recipients to verify that the email they received was indeed sent by the claimed sender and has not been modified or tampered with during transmission. This helps in building trust between senders and recipients, as well as in protecting against phishing attacks and other forms of email fraud. DKIM helps improve email deliverability by enhancing the reputation of legitimate senders. Email servers often use DKIM authentication as one of the factors to determine whether an email should be delivered to the recipient's inbox or flagged as spam. By implementing DKIM, senders can demonstrate their commitment to email security and authenticity, thereby increasing the chances of their emails reaching the intended recipients' inboxes.
Another advantage of DKIM is its role in building sender reputation. Email service providers and spam filters take into account the presence of DKIM signatures when assessing the trustworthiness of senders. Emails that pass DKIM authentication are more likely to be considered legitimate and are less likely to be marked as spam. This helps legitimate senders maintain a positive sender reputation and ensures that their emails have a better chance of reaching the inbox rather than being filtered out or blocked.
DKIM is also one of the essential building blocks for those seeking to deploy a DMARC policy for the sending domains. You can learn more about how DMARC and DKIM work together as we have created an entire section that tackles DMARC from Start to finish.
DKIM is available by default on all GlowHost Web Hosting packages and can be set up with a few clicks in your web site control panel.