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SPF and DKIM alignment explainer

Compare a visible From domain with Mail From and DKIM signing domains under relaxed or strict alignment.

The identifiers are compared only in your browser.
At least one identifier aligns
SPF alignment YesDKIM alignment Yes

This educational checker recognises common multi-label public suffixes but is not a full Public Suffix List implementation. A real DMARC evaluator also requires SPF or DKIM authentication to pass.

Use the result carefully

DMARC decisions depend on public DNS, receiver behaviour and real authentication results. Use this output as a focused diagnostic aid, then confirm changes through DNS and subsequent aggregate reports.

Getting started →Read the DMARC guides →