Have you ever received an email and wondered, “Did this really come from who it claims to?”
DKIM (DomainKeys Identified Mail) helps answer that question.
It’s an email authentication protocol that ensures your emails haven’t been tampered with during transit and proves they’re genuinely from you. Think of it as your email’s digital signature.

How DKIM Works
At its core, DKIM adds a cryptographic signature to every email sent from your domain.
When the email is received, the recipient’s mail server uses this signature to confirm two things:
Authenticity: The email was sent by an authorised sender.
Integrity: The email wasn’t altered in transit.
Here’s a simplified explanation of the process:
Adding the Signature: Your mail server attaches a unique digital signature to the email header. This signature is generated using a private encryption key stored securely on your server.
Publishing the Key: Your domain’s DNS record contains the corresponding public key, available for anyone to verify the email.
Verification: The recipient’s server uses the public key to check if the email’s signature matches. If it does, the email is trusted.
Why DKIM Matters for Your Business
DKIM isn’t just tech for tech’s sake—it’s an essential tool for safeguarding your email communications. Here’s why:
Prevents Email Tampering: Ensures your email content remains unchanged during transit, protecting your messages from being intercepted and altered.
Builds Trust: Recipients can trust that emails from your domain are genuine, strengthening your brand reputation.
Blocks Spoofing and Phishing: Makes it much harder for cybercriminals to impersonate your domain.
Boosts Deliverability: Helps your emails avoid spam filters by proving they’re legitimate.
DKIM in Action with DMARC and SPF
DKIM works best alongside SPF (which verifies the sender) and DMARC (which enforces email authentication policies). Together, they create a comprehensive defence against phishing and spoofing attacks.
SPF: Says, “Only authorised servers can send emails on my behalf.”
DKIM: Says, “This email hasn’t been tampered with and is genuinely from me.”
DMARC: Says, “Here’s what to do with unauthorised emails.”
Why Your Business Needs DKIM
In today’s digital landscape, email fraud isn’t just a possibility—it’s a persistent threat. Without DKIM, scammers can easily impersonate your domain, leading to reputational damage, lost business, and compromised customer trust. Implementing DKIM is a proactive way to protect both your business and your clients.
DKIM is more than a nice-to-have—it’s a must-have. If you want your emails to be trusted, tamper-proof, and secure, it’s time to implement DKIM. Because trust in your emails means trust in your brand.