Plain-English DMARC help for business owners and IT teams. Learn how DMARC stops email impersonation, get to p=reject safely, and check any domain for free.https://dmarc.experten-ushttps://dmarc.expert/blog/dmarc-google-workspacehttps://dmarc.expert/blog/dmarc-google-workspaceSet up SPF, DKIM and DMARC for a Google Workspace domain: the SPF record, generating a 2048-bit DKIM key in the Admin console, timing, and the DMARC record.Sat, 03 Oct 2026 00:00:00 GMTGoogle WorkspaceRollouthttps://dmarc.expert/blog/dmarc-microsoft-365https://dmarc.expert/blog/dmarc-microsoft-365Set up SPF, DKIM and DMARC for a Microsoft 365 domain: the exact records, where to turn on DKIM, the onmicrosoft.com domain, and how Microsoft treats p=reject.Sat, 03 Oct 2026 00:00:00 GMTMicrosoft 365Rollouthttps://dmarc.expert/blog/dmarc-reports-not-arrivinghttps://dmarc.expert/blog/dmarc-reports-not-arrivingA reporting service only gets your DMARC reports if it has authorized your domain in DNS. Without it, reports vanish silently. How to check, and how to fix it.Sat, 03 Oct 2026 00:00:00 GMTReportingTroubleshootinghttps://dmarc.expert/blog/gmail-yahoo-outlook-sender-requirementshttps://dmarc.expert/blog/gmail-yahoo-outlook-sender-requirementsGmail, Yahoo and Outlook.com now require SPF, DKIM and DMARC from bulk senders, and reject mail that falls short. The rules side by side, and what to do.Sat, 03 Oct 2026 00:00:00 GMTStandardsEmail securityhttps://dmarc.expert/blog/find-your-dkim-selectorhttps://dmarc.expert/blog/find-your-dkim-selectorEvery DKIM key lives at a selector, and DNS will not list them. How to read it from a message header, plus verified selectors for 14 common email providers.Sat, 03 Oct 2026 00:00:00 GMTDKIMTroubleshootinghttps://dmarc.expert/blog/mta-sts-and-tls-rpt-explainedhttps://dmarc.expert/blog/mta-sts-and-tls-rpt-explainedDMARC protects who can send as you. MTA-STS protects mail on its way to you. What MTA-STS and TLS-RPT do, and how to roll them out without losing mail.Sat, 03 Oct 2026 00:00:00 GMTMTA-STSEmail securityhttps://dmarc.expert/blog/bimi-after-p-rejecthttps://dmarc.expert/blog/bimi-after-p-rejectBIMI puts your verified logo next to your emails, but only once DMARC is enforced. What BIMI and a VMC are, and why they are the visible payoff for getting DMARC right.Wed, 12 Aug 2026 00:00:00 GMTBIMIEnforcementhttps://dmarc.expert/blog/dmarc-for-subdomains-and-parked-domainshttps://dmarc.expert/blog/dmarc-for-subdomains-and-parked-domainsThe sp and np tags, and why a domain that sends no mail still needs DMARC. How to lock down subdomains and parked domains so nobody can spoof them.Wed, 29 Jul 2026 00:00:00 GMTSubdomainsStandardshttps://dmarc.expert/blog/dmarc-breaks-forwarding-mailing-listshttps://dmarc.expert/blog/dmarc-breaks-forwarding-mailing-listsWhy forwarding, mailing lists and outside senders fail DMARC alignment, what aggregate reports reveal about each, and how to fix them without loosening your policy.Wed, 15 Jul 2026 00:00:00 GMTTroubleshootingAlignmenthttps://dmarc.expert/blog/spf-too-many-dns-lookupshttps://dmarc.expert/blog/spf-too-many-dns-lookupsSPF caps you at 10 DNS lookups, 2 void lookups and 255 characters per string. Cross the line and SPF fails. How to spot it, and how to fix it without breaking mail.Wed, 01 Jul 2026 00:00:00 GMTSPFTroubleshootinghttps://dmarc.expert/blog/dns-tree-walk-dmarcbishttps://dmarc.expert/blog/dns-tree-walk-dmarcbisDMARCbis swaps the Public Suffix List for a DNS Tree Walk to find your policy, capped at eight queries. What that changes, and why your subdomains need their own records.Wed, 17 Jun 2026 00:00:00 GMTStandardsDMARCbisSubdomainshttps://dmarc.expert/blog/dmarcbis-rfc-9989https://dmarc.expert/blog/dmarcbis-rfc-9989DMARCbis published in May 2026 as RFC 9989, 9990 and 9991, replacing RFC 7489. What actually changes for your records, and why there is nothing to panic about.Wed, 03 Jun 2026 00:00:00 GMTStandardsDMARCbishttps://dmarc.expert/blog/diy-dmarc-vs-servicehttps://dmarc.expert/blog/diy-dmarc-vs-serviceAn honest look at DMARC by hand versus a monitoring service, across reading reports, spotting alignment failures, deciding when to tighten, and time cost.Wed, 06 May 2026 00:00:00 GMTServiceRollouthttps://dmarc.expert/blog/why-dmarc-projects-stall-at-p-nonehttps://dmarc.expert/blog/why-dmarc-projects-stall-at-p-noneDMARC projects rarely fail loudly. They stall quietly at p=none because nobody parses the reports or owns the next step. Here is why, and how to fix it.Wed, 22 Apr 2026 00:00:00 GMTRolloutReportinghttps://dmarc.expert/blog/how-to-read-a-dmarc-reporthttps://dmarc.expert/blog/how-to-read-a-dmarc-reportWhat is inside a DMARC aggregate report, how to read pass and fail by sending source, and why doing this by hand across dozens of receivers does not scale.Wed, 08 Apr 2026 00:00:00 GMTReportinghttps://dmarc.expert/blog/quarantine-to-rejecthttps://dmarc.expert/blog/quarantine-to-rejectHow to tighten a DMARC policy in stages: move to p=quarantine, watch the reports, use t=y to test, and only reach p=reject once nothing legitimate is failing.Wed, 25 Mar 2026 00:00:00 GMTRolloutEnforcementhttps://dmarc.expert/blog/align-spf-dkimhttps://dmarc.expert/blog/align-spf-dkimA practical guide to making your return-path and DKIM signing domain match your visible From address, with the common alignment breakers and the fix for each.Wed, 11 Mar 2026 00:00:00 GMTAlignmentSPFDKIMhttps://dmarc.expert/blog/start-with-p-none-audithttps://dmarc.expert/blog/start-with-p-none-auditBefore you block a single message, publish p=none and collect a few weeks of DMARC reports. Here is what p=none does, and what the first reports tell you.Wed, 25 Feb 2026 00:00:00 GMTRolloutReportinghttps://dmarc.expert/blog/what-dmarc-alignment-meanshttps://dmarc.expert/blog/what-dmarc-alignment-meansWhy SPF or DKIM passing is not enough on its own, how relaxed and strict alignment differ, and a worked example of mail that passes a check but still fails DMARC.Wed, 11 Feb 2026 00:00:00 GMTAlignmentFundamentalshttps://dmarc.expert/blog/spf-dkim-dmarc-explainedhttps://dmarc.expert/blog/spf-dkim-dmarc-explainedThe three DNS records behind email authentication, what each one actually proves, and how they work together to stop people forging your domain.Wed, 28 Jan 2026 00:00:00 GMTFundamentalsSPFDKIMhttps://dmarc.expert/blog/how-email-spoofing-workshttps://dmarc.expert/blog/how-email-spoofing-worksWhy plain email lets anyone forge your From address, the real damage spoofing does to a business, and how a DMARC policy shuts it down at the receiver.Wed, 14 Jan 2026 00:00:00 GMTImpersonationEmail security