Plain-English guides to email security, DMARC, and protecting your domain - no jargon, no filler.
email domain health check
An email domain health check is a structured technical audit that verifies SPF, DKIM, DMARC, MX records, TLS/MTA-STS configuration, and blacklist status, then returns a prioritised list of fixes you can act on promptly. Run one now if you have not done so recently. The three things to do
spf dkim dmarc checker
Run dig TXT yourdomain.com for SPF, dig TXT _dmarc.yourdomain.com for DMARC, and inspect outbound message headers for DKIM signatures. That three-step check gives you an accurate picture of your domain’s authentication status in under five minutes. If anything looks wrong, or if you want ongoing visibility
fully qualified domain name
TL;DR:A fully qualified domain name is the complete, unambiguous address of a host used in DNS and email authentication. Proper FQDN management is essential for DMARC, SPF, and DKIM alignment, ensuring domain security and reliable email delivery. A fully qualified domain name (FQDN) is the complete, unambiguous address
spf fail
TL;DR:An SPF fail occurs when the sender’s IP address is not listed in the domain’s SPF record, risking email spoofing. Without DKIM and DMARC, SPF failures alone do not reliably prevent impersonation or ensure message safety. Sealedmail offers weekly expert-reviewed reports to monitor and address SPF
how to stop email spoofing
Stopping email spoofing requires deploying three DNS-based protocols in combination: SPF, DKIM, and DMARC. The NCSC recommends all three as the foundation of domain-level email authentication, supplemented by MTA-STS and TLS-RPT for transit security. No single protocol is sufficient on its own. The core steps for UK domains are: * Publish
how to setup dkim
Setting up DKIM (DomainKeys Identified Mail) means generating a cryptographic key pair, publishing the public key in your domain’s DNS as a TXT record, and enabling your mail service to sign outgoing messages with the private key. Here is the process at a glance: * Generate your DKIM key pair
dmarc failing
DMARC fails when the authentication checks on SPF and DKIM do not pass, or when those checks pass but the authenticated domain does not align with the visible “From” address in the email header. The result is that receiving mail servers treat your message as suspicious, routing it to spam
Practical guides
SPF, DKIM and DMARC all live in DNS, and most authentication failures come down to how those records are published rather than the policy itself. This guide covers where each record goes, the common hosting mistakes, and how to check your work.
domain reputation
TL;DR:Domain reputation is a trust score based on email authentication, sending behavior, and complaint history. It determines whether your emails reach the inbox or end up in spam, especially crucial for Welsh organizations handling sensitive information. Regular audits, proper authentication setup, and progressing DMARC policies are vital to
dkim check
TL;DR:A DKIM check verifies that your domain’s DKIM record is correctly published and that outgoing emails are properly signed. Regularly monitoring both DNS records and live email headers is essential to maintain email security and deliverability. A DKIM check is the process of verifying that your domain’
dkim fail
TL;DR:A DKIM fail occurs when the recipient’s server cannot verify the email’s cryptographic signature, indicating possible tampering or configuration issues. Most failures result from missing or incorrect DNS records, key mismatches, or message modifications after signing. Regular monitoring, proper DNS setup, and cautious key rotation help
dmarc checker
Comparing DMARC monitoring services by trial and error wastes time and leaves domain security gaps unchecked. Most DMARC checker tools insist on dashboard logins, technical reports, or tiered pricing that penalises organisations with more domains. This side by side comparison explains reporting style, expert involvement, and real world costs so
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