Right now, criminals may be able to send emails that look like they come from your business. If your domain doesn't have DMARC configured, there's nothing stopping them. Your clients, suppliers, and staff become targets — and your reputation takes the hit.
What Is DMARC — and Why Does It Matter?
DMARC (Domain-based Message Authentication, Reporting and Conformance) is an email security protocol that sits on top of SPF and DKIM. Together, these three standards form the foundation of email authentication for any business domain.
Think of it like a security guard for your email address. Without it, anyone can send an email that appears to come from your domain — your suppliers, your bank, or even your own MD. With it, receiving mail servers can verify whether an email actually originated from your systems, and reject or quarantine anything suspicious.
The three authentication layers every UK business needs:
- SPF — declares which mail servers are authorised to send on your behalf
- DKIM — adds a cryptographic signature to outgoing emails so they can't be tampered with
- DMARC — ties SPF and DKIM together and tells receiving servers what to do when checks fail (monitor, quarantine, or reject)
Why UK Businesses Are Exposed Right Now
Many UK businesses have SPF in place but haven't completed the full setup. SPF alone isn't enough — it only checks where an email was sent from, not whether it was tampered with in transit. And without DMARC, there's no enforcement policy: even failed checks can still result in emails landing in inboxes.
Business Email Compromise (BEC) — where criminals impersonate your company or a trusted supplier to redirect payments or extract information — cost UK businesses millions of pounds last year. The majority of successful BEC attacks exploit domains with no DMARC policy or a DMARC policy set to p=none (monitor only, no action).
The good news: Full DMARC, SPF, and DKIM configuration typically takes one to two hours of IT time, costs nothing in software, and doesn't interrupt your email service when done correctly. It's one of the highest-impact, lowest-cost security changes a UK business can make.
Ben's Take: What This Means for Leaders
When I talk to business leaders about email security, most assume their IT team has "sorted it." In reality, incomplete authentication is one of the most common gaps I see — even in businesses that have good IT support in other areas.
The risk isn't just to your own inbox. A domain without DMARC enforcement can be used to target your clients and suppliers with convincing fake emails. That's a reputational and contractual liability, not just a technical one.
The first step is to find out where you actually stand. Run a check on your domain now — it takes 60 seconds and will show you exactly what's in place and what's missing.
Find Out If Your Domain Is Open to Fraud
Check your email authentication in 60 seconds. See whether SPF, DKIM, and DMARC are correctly configured — and get a clear picture of your exposure before a fraudster finds it first.
Check My Domain Free Book a Call with Ben →Not sure what your results mean or how to fix what's missing? Book a 20-minute call with Ben Richards at SecureMyEmails. We'll walk through your domain setup and tell you exactly what needs doing — no jargon, no upsell, just a clear action list.
For the full step-by-step DMARC setup guide — including DNS record examples, common mistakes, and how to move from p=none to p=reject safely — read the original article on Good Choice IT:
DMARC Setup for UK Businesses: Improve Deliverability & Stop Business Email Fraud →
Originally published on: Good Choice IT
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