What is DKIM? How to set it?

1. What is DKIM?
2. Why do you need a DKIM signature
3. How DKIM Works
4. How to set up a DKIM signature
5. DKIM Signature Verification
6. Key points

What is DKIM?

DomainKeys Identified Mail (DKIM)  is an email verification technology that enables your domain to digitally sign outbound messages. This digital signature serves as a unique identifier, allowing mail providers to verify that the email was indeed sent from your authorized sources. By verifying the authenticity of your emails, DKIM helps combat phishing and spoofing attempts, protecting your brand reputation and safeguarding your recipients from malicious activities.

A DKIM signature is a TXT record that is added to the site's DNS zone settings. The entry itself looks like this:

us._domainkey  TXT  v=DKIM1; k=rsa; p=XXXXXXXXXXXXXXXXXXXXX,

where v — DKIM version, always takes the value v=DKIM1;

k — key type, always k=rsa;

p — unique code that can be generated in the mailing service.

Why do you need a DKIM signature

• Protects from scammers
  A DKIM signature will prevent spammers from sending emails on your behalf. Together with SPF and DMARC, this technology will protect your subscribers from fraudsters, including identity theft.

• Increases deliverability
  DKIM improves domain reputation. Using DKIM, the receiving server determines the authenticity of the sender and its overall rating. Emails with a good reputation are more likely to end up in the inbox.
  DKIM works like an ID: you present it to the mail provider, and he lets you into the inbox.
• Gives access to postmasters
  Postmasters are mail services for mailing analytics. They help track deliverability, opens, unsubscribes, and spam complaints. To enable statistics in the postmaster, you must have email authentication configured. DKIM is one of the components of email authentication.

How DKIM Works

DKIM works like this: the letter contains encrypted data about who and when the letter was sent. The mail provider receives this data along with the letter. The provider decrypts them using the public key posted on the domain from which the letter was sent. If the data matches, then this is an honest sender, the letter can be skipped to the Inbox. If not, it is a scammer, the letter goes to Spam.

How to set up a DKIM signature

Setting up DKIM involves accessing the site's DNS zone and corporate email. Typically, SPF and DKIM records are generated in the email service provider's dashboard and added through the hosting provider's account.

1. Generate DKIM Records: Create a DKIM record within your email service provider's settings.

2. Add to DNS Settings: Insert the generated DKIM record into your domain's DNS settings. The record includes essential details such as the DKIM version, key type, and a unique code.

DKIM Signature Verification
After setting up a DKIM signature, it's worth checking if it works correctly. This can be done using our service, if your mailbox is connected to Warmy using "Check DNS records" test, or using third-party services, such as Mailtester.

MailTester.com - a service with which you can test a letter, including verifying the DKIM signature. MailTester gives you a complete deliverability report and also checks your email authentication settings.
You will be prompted to send a test email to the provided email address, after which you will be able to receive a detailed report about your mailbox.
All this will be evaluated on a scale from 1 to 10, where 1 - you are most likely to land in the SPAM folder, and 10 - you will definitely get into your recipient's Inbox.

Key points

Here is a table summarizing the key points of the article: