Testers

SPF / DKIM / DMARC Checker

Check SPF, DKIM and DMARC alignment for a domain — the three pillars of email authentication.

About Mail Auth Check

Checks SPF, DKIM, and DMARC configuration for a domain together and evaluates whether they're properly aligned — not just present, but consistent with each other in the way DMARC alignment actually requires. A domain can have valid SPF and a valid DKIM key independently and still fail DMARC if the alignment between the From header domain and the authenticated domains doesn't match up. Complements the SPF Builder and DMARC Builder tools — build the records there, then verify the full picture actually aligns here.

DKIM selectors aren't publicly discoverable by design — if the default selector guess doesn't find a key, that doesn't mean DKIM isn't configured, only that this particular guess missed; check with the domain's mail administrator for the exact selector in use.

📖 Read more in our Knowledge Base →

DKIM Selectors

Common selectors to try:
default, google, mail, smtp, dkim, k1, s1, s2, selector1, selector2, pm, mimecast

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