--- title: "What Is Dkim And Why You Should Use It To Secure Your Email | DuoCircle" description: "Digital keys are the keys to email authentication, which basically means they verify you’re actually the person who sent the email you claim to be." image: "https://www.duocircle.com/images/og-default.png" canonical: "https://www.duocircle.com/blog/email-hosting/what-is-dkim-and-why-you-should-use-it-to-secure-your-email/" --- Quick Answer DKIM (DomainKeys Identified Mail) is an email authentication protocol that lets a domain owner sign outgoing mail with a private key, so receivers can verify the signature against a public key published in DNS. If the signature validates, the receiver knows the message was authorized by the domain and was not modified in transit. DKIM survives forwarding (unlike SPF, which breaks when a forwarder rewrites the envelope sender), which is why it is the more durable of the two and forms the basis of DMARC alignment for forwarded mail. Implement it by generating a 2048-bit key pair, publishing the public key as a TXT record at selector.\_domainkey.yourdomain.com, and configuring your mail platform to sign every outbound message. Share [ ](https://www.linkedin.com/sharing/share-offsite/?url=undefined%2Fblog%2Femail-hosting%2Fwhat-is-dkim-and-why-you-should-use-it-to-secure-your-email%2F "Share on LinkedIn") [ ](https://twitter.com/intent/tweet?text=What%20Is%20Dkim%20And%20Why%20You%20Should%20Use%20It%20To%20Secure%20Your%20Email&url=undefined%2Fblog%2Femail-hosting%2Fwhat-is-dkim-and-why-you-should-use-it-to-secure-your-email%2F "Share on X/Twitter") [ ](https://www.facebook.com/sharer/sharer.php?u=undefined%2Fblog%2Femail-hosting%2Fwhat-is-dkim-and-why-you-should-use-it-to-secure-your-email%2F "Share on Facebook") [ ](https://reddit.com/submit?url=undefined%2Fblog%2Femail-hosting%2Fwhat-is-dkim-and-why-you-should-use-it-to-secure-your-email%2F&title=What%20Is%20Dkim%20And%20Why%20You%20Should%20Use%20It%20To%20Secure%20Your%20Email "Share on Reddit") [ ](mailto:?subject=What%20Is%20Dkim%20And%20Why%20You%20Should%20Use%20It%20To%20Secure%20Your%20Email&body=Check out this article: undefined%2Fblog%2Femail-hosting%2Fwhat-is-dkim-and-why-you-should-use-it-to-secure-your-email%2F "Share via Email") ![Secure Your Email](https://media.mailhop.org/duocircle/images/2022/07/spf-record-7574.jpg) Digital keys are the keys to email authentication, which basically means they verify you’re actually the person who sent the email you claim to be. While Google, Yahoo, and Microsoft all offer their own versions of digital keys, the most popular one is DKIM, which stands for _DomainKeys Identified Mail_. Basically, DKIM is a set of parameters for digital keys, which let email recipients know they are who they claim to be. Because the DKIM keys are stored in servers, the authentication works even if your email is hacked. DKIM stands for DomainKeys Identified Mail and is used for the authorization of an email from which the sender is ready to be confident. Like SPF, DKIM is an open protocol for email authentication that is utilized to align DMARC. A [DKIM record](/resources/what-is-dkim) can be found in the DNS, but many parts are more sophisticated than SPF. DKIM’s chief advantage is that it can go through their forwarding without being diminished by any forwarding and gives a base for making email secure. The DomainKeys convention became a reality in 2004 after Yahoo and Cisco merged their Identified Internet Mail initiative. It has since been widely adopted to encourage email security. ## What is a DKIM Record? A domain owner adds a DKIM record, which is a variation of an TXT record, to the DNS records of the sending domain. This [TXT record](https://support.google.com/a/answer/183895?hl=en) includes a public key which is used by receiving mail servers to **verify a message’s signature.** It is often given to you by the company that is responsible for your email. [![DNS records](https://media.mailhop.org/duocircle/images/2022/07/spf-record-tester-7575.jpg)](https://media.mailhop.org/duocircle/images/2022/07/spf-record-tester-7575.jpg) ## What is a DKIM Signature? DKIM provides email headers that can be added to an email and included with encryption. Each DKIM signature contains the information needed for an email server to _verify the signature_ is real and is encrypted by a pair of DKIM keys. The originating email server has the web address known as the private DKIM key, into which the receiving mail server or Internet service provider can check to sign and receive emails. These signatures travel with the emails and are verified by email servers as they travel all the way to the intended recipient. ## How does DKIM work? When an inbound mail server receives a message, it will find the DKIM signature and look up the sender’s public DKIM key in DNS. The variable or DKIM selector provided in the DKIM signature is used to determine where to look up for this key. If the key is found, it can be used to extract the [DKIM signature](https://www.dmarcanalyzer.com/dkim/dkim-signature/). This is then compared to the values received by the message. If the values match, the signature is authentic and the message has not been altered. ## Why use DKIM for Email? Implementing DKIM for email provides many benefits in regards to email security. - _Protection of message integrity is one of the main advantages delivered by using DKIM._ - _Another result is an increase in domain reputation and email deliverability._ - _One of the foundational methods of authenticating email for DMARC is DKIM._ [![DKIM for Email](https://media.mailhop.org/duocircle/images/2022/07/hosted-email-server-7576.jpg)](https://media.mailhop.org/duocircle/images/2022/07/hosted-email-server-7576.jpg) ## What happens when DKIM fails? The indiscriminate conveyance of an email when DKIM alignment fails or when the d value in the Header From does not match the d value in the DKIM signature can cause deliverability issues. Mailbox providers might send the message to the spam folder or send the message that’s blocked completely. It is essential to inspect all failed messages to identify the origin of the email launch, regardless of whether the sending domain is authentic or false. In addition, take note of any invalid messages which may have been sent out from the DKIM configuration of the domain. ## Why DKIM-Only Isn’t Safe Enough DKIM on its own isn’t reliable enough to authenticate the identity of the email sender and does nothing to **prevent the spoofing of the domain** visible in the header of the email. DMARC solves the problem by requiring that the overall domain to which the end user addresses a message is properly certified. In conclusion, DKIM (DomainKeys Identified Mail) is a privacy-enhancing feature for [PGP encryption](https://www.varonis.com/blog/pgp-encryption). It is a method for adding digital signatures to email messages, making it harder for spam and phishing messages to pass as legitimate emails. DKIM adds digital signatures, the header HTML tag, and the footer text to the message. This signature lets the receiver know that the message is really from the DKIM-trusted domain. ![Brad Slavin](https://media.mailhop.org/dmarcreport/images/team/brad-slavin.jpg) Brad Slavin General Manager General Manager at DuoCircle. Product strategy and commercial lead across the email security portfolio. ## Secure your email infrastructure Protect, authenticate, and deliver. Contact our team to find the right solution. [Contact Sales](/contact/) [Explore Products](/products/) ## Related Articles [ Email Hosting 18m 10 Steps To Set Up A Self-Hosted Mail Server Without Hitting Spam Mar 10, 2026 ](/blog/email-hosting/10-steps-set-up-self-hosted-mail-server-avoid-spam/)[ Email Hosting 5m The 9 Ways You Benefit from Moving Mail to the Cloud Apr 13, 2016 ](/blog/email-hosting/9-ways-benefit-moving-mail-cloud/)[ Email Hosting 1m Amazon Order Confirmation Trojan Feb 16, 2019 ](/blog/email-hosting/amazon-order-confirmation-trojan/)[ Email Hosting 6m Apache Log4j Zero-day Vulnerability: How to Detect it & Precautions You Need to Take Dec 24, 2021 ](/blog/email-hosting/apache-log4j-zero-day-vulnerability-how-to-detect-it-precautions-you-need-to-take/) ```json {"@context":"https://schema.org","@type":"Organization","name":"DuoCircle LLC","url":"https://www.duocircle.com","logo":{"@type":"ImageObject","url":"https://www.duocircle.com/images/duocircle-logo.png"},"description":"DuoCircle is a portfolio of specialized email products covering protection, authentication, delivery, and routing. 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