Gmail, Yahoo and Outlook sender requirements: what you need
Gmail, 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.
Read postDMARC for subdomains and domains that do not send email
The 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.
Read postThe DNS Tree Walk in DMARCbis, and what it means for your subdomains
DMARCbis 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.
Read postDMARCbis is here: what RFC 9989 changes and what it does not
DMARCbis 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.
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