ServerRecords
Articles
Practical guides on DNS, email authentication and domain security.
Reading DMARC Reports: Turn Raw XML Into a Path to p=reject
DMARC aggregate reports arrive as compressed XML nobody can read by hand. Learn how to parse them, spot spoofers, and safely move your domain to p=reject.
Read →Mapping Subdomains with Certificate Transparency Logs
How the CT Subdomain Resolver reads public certificate logs to find forgotten subdomains, resolve their live IPs, and audit your real attack surface.
Read →SPF Flattening: How to Beat the 10-Lookup Limit Without Breaking Email
Too many DNS lookups in your SPF record triggers PermError and sends legitimate mail to spam. Learn how SPF flattening works, when to use it, and its risks.
Read →Reading Email Headers: How to Trace a Message and Spot a Fake
Learn to read raw email headers, trace a message hop by hop, check SPF/DKIM/DMARC results, and catch spoofing with the ServerRecords Mail Header Analyzer.
Read →SPF, DKIM, and DMARC: A Practical Guide to Email Authentication and Deliverability
How SPF, DKIM, and DMARC work together to prove your mail is genuine, keep it out of spam, and stop spoofing of your domain. A step-by-step setup guide.
Read →What a Domain Health Check Actually Tells You
One scan covers registration, DNS, HTTPS redirects and security headers. Learn what a domain health check surfaces and why each result matters.
Read →Email Health Check: One Lookup for MX, SPF, DMARC, and TLS
Run one domain lookup to see whether your MX, SPF, DMARC, MTA-STS, and TLS-RPT records are configured correctly and where your email is exposed.
Read →Blacklist Lookup: How to Check If Your Mail Server IP Is on a DNSBL
Check your server IP against major DNSBLs, understand how reverse-DNS blacklist queries work, learn why clean IPs get listed, and how to get delisted.
Read →Reading a Domain in One Pass: A Guide to Full DNS Record Lookups
See every DNS record for a domain at once - A, MX, TXT, SPF, DMARC, CNAME, NS, SOA, CAA, SRV and WHOIS - and learn what each one actually does.
Read →Picking a RAID Level: Capacity, Redundancy, and the Math Behind It
Compare RAID 0, 1, 5, 6, and 10 by usable capacity, fault tolerance, and efficiency, with the formulas and a worked example, so you can size an array with confidence.
Read →Subnetting Without the Binary Headaches: A Practical CIDR Guide
Understand CIDR prefixes, subnet and wildcard masks, network and broadcast addresses, and usable host ranges for IPv4 and IPv6, without doing the binary by hand.
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