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In a nutshell, DKIM means Domain Keys Identified Mail. So this means Authenticate e-mail with DKIM, to ensure that messages aren’t modified in transit and, to make sure that they come from a legitimate source. Create DKIM record at your domain’s DNS settings to help fight email spoofing and phishing and increase deliverability.
With DKIM, it is possible for recipients mail server to verify whether an email has been authorized by the domain owner and has not existed in any possible form of tampering. This could satisfy one of the many standards around the globe when it comes to secure email like Sender Policy Framework (SPF) and Domain-based Message Authentication, Reporting & Conformance (DMARC).
How Does DKIM Work?
DKIM adds a digital signature to the message headers as soon as the email leaves the sender. Signature generated private cryptographic key with which your domain holds. The public key is then published as a DNS record and this is what the recipient’s mail server uses to verify authenticity of the signature.
In a few simple steps DKIM process can be simplified into:
- Signing the email: When you send an email, your mail server applies a private key to create a unique cryptographic signature for that specific message, and this signature is included in the header of the email.
- Sending that email: The email is sent together with that signature, which is attached to the email while the email itself remains intact.
- Recipient Verification: The public key associated with that sender’s domain is accessed by the receiving mail server from its DNS records. It employs the public key to decrypt the signature and authenticate the fact that the message has not been altered after sent.
- Pass/Fail: If the DKIM check passes, the message is regarded as having passed all validity tests. Otherwise, the mail server receiving the mail may treat it as suspicious or it may even be flagged as spam.
Why Are DKIM Records Important?
There are many important roles that DKIM plays in emails:
- Prevent tampering of the emails: One of the most significant works done by DKIM is that it prevents tampering of e-mails. As per the cryptographic signature, the information contained in the message will not alter when transgression occurs. And if he tries to change anything to mails while transit, DKIM check will be not-performed and the message gets flagged as equipment fraud.
- Works Against Phishing or Spoofing: Email spoofing is often employed by cybercriminals send e-mails that look as though they’re coming from legitimate domains. When you implement DKIM, then you basically tell the email recipients that your emails are authorized, making it that much harder for the malicious actors to impersonate your domain.
- Increases deliverability: Email providers such as Gmail, Yahoo, and Microsoft are always looking to block spam. Without DKIM set up on your domain, your emails are more likely to go in the spam folder. Using DKIM records proves that your emails are legitimate, improving your chances of going into the inbox.
- The Domain-based Message Authentication, Reporting, and Conformance (DMARC) email security protocol is designed to reduce email-based attacks, and DKIM is an important part of it. Implementing DKIM allows the use of a DMARC policy, giving added protection to your email domain.
How to Create DKIM Records
To create DKIM for your domain, you have to set DNS settings to ensure the addition of the TXT record. Here are the steps:
- Generate a DKIM Key Pair: You would require two keys, that is a public key and a private key. The public key is the one that you publish on your DNS records, while the private key is stored on your email server. With Google Workspace, Microsoft 365, and some other providers, generating these keys should be fairly simple.
- Add the DKIM Record to Your DNS: After obtaining the DKIM public key, add a new TXT record to the domain DNS settings. The TXT record will contain the public key and will be used by receiving mail servers to validate your email messages.
- Add the DKIM Record to Your DNS: Once you have the public key, add a new TXT record to your domain’s DNS settings. The TXT record will include the public key and will be used by receiving mail servers to verify your email messages.
A sample DKIM TXT Record setup is as follows:
default._domainkey.yourdomain.com IN TXT "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9..."
In this case:
– `default._domainkey.yourdomain.com` is the TXT Record.
– The value (`v=DKIM1; k=rsa; p=…`) identifies DKIM version number DKIM1, key type RSA, and public key (`p=`).
In order to give evidence of DKIM signing on that mail server, you need to activate DKIM signing through the email service provider after having added the TXT record to your DNS. This has to do with the platform you are on. If you’re a Google Workspace user, see the Admin console to activate DKIM signing.
- To Verify the DKIM Record: After DKIM has been configured, one thing to ensure is to test whether the DKIM record is working properly. MXToolbox or American may be used to check for DKIM signature validity and the proper DNS configuration.
DKIM, SPF, and DMARC Represent a Trio to Guard Emails
While DKIM on its own is powerful, it works best when combined with SPF and DMARC:
– SPF (Sender Policy Framework): SPF assists in determining whether an IP address is authorized to send an email on behalf of the domain. It is similar to DKIM in that it attempts to stop email spoofing.
– DMARC: DMARC builds in SPF and DKIM alike. It empowers domain owners to request what should happen to the email based on its authentication failure: to reject, to quarantine, or to simply take note. DMARC also provides reporting capabilities, allowing you to know who is sending emails claiming to be from your domain.
Common Issues with Implementing DKIM
While the configuration of DKIM would seem fairly simple, a host of common issues arise:
- Invalid DNS Records: If the public key isn’t correctly configured in your DNS settings, the DKIM signature won’t be verifiable.
- Email Forwarding: In some cases, by forwarding the email, DKIM might break, since some email forwarding will modify the email envelope and/or headers.
- Multiple Mail Servers: IIf you use several systems for emailing (let’s say for marketing or news…) then you could interfere with DKIM signature verification.
It is very important to establish DKIM records for securing emails. DKIM would authenticate your mails, protecting your domain from being used for phishing and spoofing attacks, improving its deliverability, and enhancing its overall reputation. DKIM guarantees the trustworthiness of your messages, and it’s also an important component in the overall ecosystem for email security.
Your domain will be safe by setting up DKIM with SPF and DMARC to ensure the good quality of email communications with lesser chances of malicious activities.