Fixes for the exact error you're staring at
One page per real DMARC, SPF, and DKIM problem — the query or rejection message, explained, with the exact fix and a free tool to confirm it worked.
DMARC alignment explained: why SPF/DKIM can pass and DMARC still fail
DMARC only counts SPF or DKIM when the authenticated domain matches the From address people see. Here is how alignment works and how to fix a pass that still fails DMARC.
Verified Sep 26, 2026
Read the fix →How to read DMARC aggregate (rua) reports
DMARC rua reports are daily XML dumps of who sent as your domain and whether SPF/DKIM aligned. Here is what to look at first, and what to ignore.
Verified Sep 26, 2026
Read the fix →SPF vs DKIM vs DMARC: what each one actually checks
SPF checks the sending IP, DKIM checks the signature, DMARC ties both to the From address you see and decides what happens on failure. Here is how they fit together.
Verified Sep 26, 2026
Read the fix →Fix Gmail error 550 5.7.26: message does not pass authentication checks
Gmail bounces mail with 550 5.7.26 when SPF and DKIM both fail DMARC alignment. Here's exactly what that means and the record fix that clears it.
Verified Aug 18, 2026
Read the fix →SPF permerror: too many DNS lookups, and how to fix it
SPF caps you at 10 DNS lookups. Over that limit, receivers treat your entire SPF record as broken. Here's how to count your lookups and cut them back under 10.
Verified Aug 18, 2026
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