What Is A DKIM Selector, And Where Can You Find It?

What Is DKIM Selector?

A DKIM Selector is especially necessary when publishing multiple DKIM records, i.e., different DKIM keys, to the domain. It is an extension to a DKIM record. A user can reuse a selector with several domains, but one particular domain can only have one public key. DKIM selectors are often alphanumeric strings formed with random characters and can fetch individual source names, server locations, and signing dates.

A DKIM Selector is required first to locate and then retrieve the public key to verify the email is genuine and authentic. While creating a DKIM signature for an email, there is a specific need to mention the private key to be used. It is specified in the header field as the ‘s=’ tag and is in all technical headers of the email.

Where Can One Find The DKIM Selector?

When a public or private key is created and DKIM is set up for an email domain, a DKIM selector is specified. Further, the selector is paired up with the DKIM Signature. If anyone wants to verify the DKIM selector, they can email themselves and follow the below steps.

Here’s how one can find the DKIM Selector

• After opening the email, check the full headers section to view the header information with the DKIM authentication results.
• In the headers section, search for ‘DKIM Signature’ applied to the message. All DKIM selectors contain the ‘s=’ tag, which includes the selector used. For instance, if given as ‘s=2013rf,’ ‘2013rf’ is the DKIM selector. In the case of multiple signature headers, find the one that includes the domain.
• If unable to find the DKIM signature header matching the specified domain, reset the settings and check again.

The above discussion has answered the question, “What is DKIM selector?” and its importance in a DKIM record. DKIM authentication adds an extra level of security to a domain. When publishing different keys with multiple DKIM records in a DNS, DKIM selectors become essential. Once the DKIM records and the selectors are appropriately set, the DKIM record can be validated using a validation tool. After the validation, it is all set to work, and there is a verified DKIM record that guarantees email authentication and protection.