What is DKIM and how to set it up?

What is DKIM (DomainKeys Identified Mail)?

The DKIM is an email authentication record that allows the receiver to know whether a particular email was indeed sent by an authorized sender.

How does it work?

DKIM record gives your emails a digital signature that gets added to your email header and is secured with encryption.

The DKIM record consists of two keys. One is a private key that is stored confidentially by the sender's email provider, and the second is a public key that the recipient's email server can retrieve from the sender's DNS. When an email is received, the recipient's email server uses the public key to verify the DKIM signature in the email header. If an authorized sender sends the email, the DKIM check is successful.

DKIM plays a vital role in your email deliverability, and therefore, it's strongly recommended to set up DKIM if you're using a business email with a domain attached.

How to check whether your email account has a valid DKIM record?

It's effortless and straightforward to check whether your email account has a valid DKIM record.
Go to the mail-tester website, and you'll see a randomly generated email address.
Copy that email address and send a test email to that email address. Please make sure you send the test email from the email you wish to check the DKIM validation.
Once the email is sent, navigate to the mail tester site and click the Check your score button, and then you will be redirected to the page which will show you deliverability insights about your email.
You can expand the email authentication, and you will be shown whether your email has a valid DKIM or not, as shown below.

How to set up the DKIM?

Please note that steps to set up the DKIM record vary for every email provider and most email providers don't even allow users to set up the DKIM on their own as it needs to be done by contacting them (email provider customer support).

Business Gmail users (Google Workspace) can set up the DKIM for their Gmail account if it's not set. However, they need to have access to the admin console of that Google Workspace account and access to the DNS manager of the domain they wish to set up the DKIM for.

Please refer to the below attached video to understand the step-by-step process of DKIM set up for a Gmail account.

Note: You can set up DKIM for your email only if your email provider is Gmail. If you're using any other email service provider, you may need to contact the customer support of your email provider to get DKIM set for your email.

Setting DKIM is not applicable if you're using a free email account like gmail.com, outlook.com, yahoo.com. You can set up DKIM only if you're using a business email that has your domain attached (i.e, [email protected]).