Domain Health Checks: What They See and What They Miss
A health check reads what is public. What that covers, what it cannot tell you, and how fast the answer goes stale.
Read the guideEmail Health CheckerReference
Guides for thefree tools.
The long version of what each tool does, why the record matters, and how to fix it when it breaks. One guide per tool, no account needed to read or to use them.
Checkers
Email Blocklists and How Delisting Works
Not every listing matters equally. Which lists providers query, how removal works, and why express delisting is a scam.
Read the guideBlocklist CheckerReading Email Headers
The five header lines that settle a deliverability question, and what a gap in the Received chain is telling you.
Read the guideEmail Header Analyzer
DNS generators
SPF Record Setup Guide
What SPF authorizes, the 10 DNS lookup limit, and how to publish a record that does not quietly break.
Read the guideSPF Record GeneratorDKIM Record Setup Guide
How DKIM signing works, why it survives forwarding when SPF does not, and how to rotate a key safely.
Read the guideDKIM Record GeneratorDMARC Record Setup Guide
What alignment means, why a passing SPF check can still fail DMARC, and the staged path from none to reject.
Read the guideDMARC Record GeneratorSPF Flattening: When It Helps and When It Bites
Flattening trades a lookup problem for a maintenance problem. When that trade is worth making, and when pruning is better.
Read the guideSPF Flattener
Reading is the slow way to find out.
LitInboxes re-checks every monitored domain every 6 hours and tells you when one of these records breaks, instead of you finding out from a customer.
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