DKIM Email Authentication

DKIM (DomainKeys Identified Mail) is an email authentication method that allows the receiving server to verify that an email was genuinely sent from your domain and has not been altered during transit. In practice, DKIM adds a digital signature to email headers during the sending process. This signature is validated by the recipient’s server using a public key stored in your domain’s DNS records (see zone records below).

Enabling DKIM improves email delivery reliability and reduces the risk of emails being flagged as spam or phishing attempts. This is especially beneficial when sending newsletters, invoices, or other critical communications to customers.

DKIM is Automatically Enabled

When the service is activated, all required configurations for DKIM authentication are automatically set up for your domain. When sending emails via any channel, the following

header information is automatically added to the email:

DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; [...]

This signature allows the recipient’s server to verify the authenticity of the email.

Why Is the DKIM Signature Missing from My Emails?

If the DKIM signature (DKIM-Signature header) is missing from your sent emails, ensure that your domain includes the following DNS records in your zone file:

• Replace omadomain.fi with your actual domain name.
• Replace omadomain-fi with your actual domain name, where periods (.) are replaced with hyphens (-).

If these records are not properly configured, DKIM authentication will fail, and the signature will not be added to outgoing emails.

Updated on: 24/08/2025