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Gmail, Yahoo and Microsoft reject or junk mail from domains that miss their sender rules. See which rules your domain meets in DNS, and which ones must be checked on a real message.
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SPF, the DKIM key and the DMARC record are read from DNS and marked as met or not met. Some rules depend on each message or on the sending servers, such as From alignment, reverse DNS, TLS, one-click unsubscribe and the spam rate. Those are listed separately with the tool that can check them; no pass or fail is invented for them.
For the full SPF, DKIM, DMARC, MTA-STS and TLS-RPT picture, use the Email Security Check.
Gmail and Microsoft use about 5,000 messages a day to their users (personal accounts) from one domain; Yahoo uses a similar threshold. Once a domain crosses it, it stays classified as a bulk sender. Every sender, whatever the volume, still needs SPF or DKIM and valid reverse DNS.
For the Gmail, Yahoo and Microsoft rules, yes: any published DMARC policy meets the minimum. It does not stop spoofing; quarantine or reject does.
The domain in the visible From address must match the DKIM signing domain (d=) or the SPF envelope domain. Sending through a service that signs with its own domain passes DKIM but fails alignment.
It is a header on each marketing message, not a DNS record. Paste a message header into the Email Header Analyzer to see whether List-Unsubscribe and List-Unsubscribe-Post are present.
Add your domain to CloudSpex to be alerted when SPF, DKIM or DMARC changes or breaks.
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