When it comes to email marketing and brand communication, there’s one ugly reality we can’t ignore — cybercriminals love to impersonate trusted brands to scam unsuspecting recipients. Without the right protections in place, your domain could be used to send fraudulent emails, damaging your reputation and tanking your email deliverability.
That’s where SPF, DKIM, and DMARC come in — three email authentication protocols that work together to prove you are who you say you are.
1. SPF (Sender Policy Framework) – The Gatekeeper
What it does:
SPF lets you specify which mail servers are authorised to send emails on behalf of your domain. Think of it as a guest list for your email club — if the sender’s server isn’t on the list, the message is flagged as suspicious.
Consider the following example:
You own brandstore.com. You send marketing emails through Klaviyo, but scammers try to send phishing emails pretending to be you from a shady server in another country. With SPF configured, the receiving mail server checks:
- Is this sending server listed in
brandstore.com’s SPF record? - If no, the email gets marked as spam or rejected before hitting inboxes.
Why it matters: Without SPF, anyone can send emails using your domain name. That means you’re leaving your brand’s identity wide open to abuse.
2. DKIM (DomainKeys Identified Mail) – The Signature Checker
What it does:
DKIM adds a digital signature to your emails. This signature is encrypted and unique to your domain, allowing receiving servers to verify that the message content hasn’t been altered in transit.
Consider the following example:
You send a product launch email. Without DKIM, a malicious middleman could intercept it, swap your “Shop Now” link with a phishing link, and forward it to your customers. With DKIM, the receiving server checks your digital signature against the one stored in your domain’s DNS records — if they don’t match, the email fails authentication.
Why it matters: DKIM ensures that what you send is exactly what your subscribers receive — no hidden edits, no malicious links.
3. DMARC (Domain-based Message Authentication, Reporting, and Conformance) – The Enforcer
What it does:
DMARC tells receiving servers what to do if SPF or DKIM checks fail — quarantine the message, reject it outright, or let it through. It also gives you detailed reports on who’s sending emails from your domain.
Consider the following example:
You set your DMARC policy to “reject.” A fraudster tries to send a fake invoice email from billing@brandstore.com using a server you’ve never approved. The email fails SPF and DKIM, so DMARC instructs the receiving server to block it before it reaches your customer.
Why it matters: DMARC is your final line of defence, ensuring unauthorised messages don’t slip into inboxes pretending to be from you.
Why Every Brand Must Set These Up
Without SPF, DKIM, and DMARC:
- Your brand can be impersonated — damaging trust overnight.
- Your emails are more likely to land in spam, even if they’re legitimate.
- You have no visibility into who’s using your domain.
With them in place:
- You protect your customers from phishing scams.
- You safeguard your sender reputation, which keeps your deliverability strong.
- You gain reports to monitor suspicious activity in real time.
Quick Setup Checklist
- SPF – Add an SPF record to your DNS listing all approved sending services.
- DKIM – Enable DKIM signing in your email platform and publish the public key in your DNS.
- DMARC – Create a DMARC record that specifies your enforcement policy and reporting address.
✅ Bottom line:
SPF, DKIM, and DMARC aren’t optional — they’re your domain’s bodyguards. If you want your emails to be trusted, delivered, and safe from impersonation, set them up today.
