Founder of SealedMail and a UK email-security specialist in DMARC, SPF, DKIM and email authentication for regulated sectors. He personally reads the DMARC and TLS reports behind every SealedMail account and writes the company's plain-English guides.
check spf record
TL;DR:Verifying your SPF record involves checking that exactly one DNS TXT record with “v=spf1” exists at your domain’s root.A proper SPF setup prevents domain spoofing, especially important as UK public sector bodies now require enforced email authentication policies. Checking your SPF record means verifying that
Practical guides
Your DMARC policy might protect your main domain while leaving every subdomain wide open. Here is how the sp tag works, why it exists, and how to set it correctly.
spf flattening
TL;DR:SPF flattening replaces include mechanisms with static IP addresses to stay within DNS lookup limits. Automating this process is essential to maintain accurate records and prevent email delivery failures caused by stale IP data. SPF flattening is defined as the process of replacing include: mechanisms in an SPF
email header analyzer
Choosing a DMARC monitoring platform that actually detects spoofing and delivers usable email authentication reports is harder than most security teams expect. Most email header analysers depend on automated dashboards and machine reporting, which means ambiguous compliance data and patchy audit evidence. This comparison explains report clarity, managed service, enforcement
email security checker
Managing email authentication and domain compliance remains complex for IT and security teams wanting actionable monitoring. Many traditional email security checkers restrict features to single domains or lack automated reporting needed for large estates. This comparison shows feature scope, reporting clarity, and automation across six DMARC monitoring platforms so IT
email reputation check
Email reputation monitoring is often unreliable when automated dashboards fail to deliver clear reports suitable for audits or investigations. Most services lack manual review or deliver inconsistent alerts, leaving gaps in compliance evidence and ongoing protection. This comparison covers the reporting methods, support level, and pricing across leading DMARC monitoring
ncsc email security check
TL;DR:The NCSC Mail Check service was a free tool that helped UK organizations verify their email authentication setup but was retired in March 2026. Organizations must now actively monitor SPF, DKIM, and DMARC records and update their DNS settings to maintain email security. Ongoing vigilance and staged policy
domain name security
TL;DR:Proper domain name security involves configuring SPF, DKIM, and DMARC to prevent email spoofing and protect organizational identity.The UK’s government mandates and phased deployment strategies have shaped best practices, stressing ongoing monitoring and enforcement.Many organizations remain vulnerable due to incomplete implementation and reliance on retired
Explainers
DMARC does not just check whether SPF or DKIM pass. It checks whether the domains they authenticate line up with the domain a person sees. This is alignment, and it is the reason legitimate email can fail DMARC.
Explainers
DMARC produces two kinds of report, and they are not equal. This explains what aggregate (RUA) and forensic (RUF) reports contain, why RUF is mostly a dead letter, and how to actually use the data.
Email spoofing
Anyone can put your domain in the From field of an email. Here is who is really sending mail in your name, and how to stop them.
DKIM
DKIM proves your email really came from you, but only if it stays valid. Here is why it needs monitoring.
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