Blog — page 11

June 29, 2026

The DMARC np tag: locking down subdomains that don't exist

DMARCbis adds the np tag for non-existent subdomains — a spoofing gap that sp never covered. What it does, how it differs from sp, and how to set it.

June 28, 2026

DMARCbis is made of three RFCs that replace 7489. What each one contains, the exact list of tags added and removed, and what it means for the record.

June 27, 2026

DMARCbis, published in May 2026, replaces RFC 7489. What the DMARC V2 revision changes (np, t, DNS Tree Walk), what stays, whether action is needed.

June 16, 2026

Banks are among the most impersonated brands, yet many still stop at p=none. Why finance is a prime target, what the data shows, and how to fix it.

June 16, 2026

A safe, staged path from DMARC monitoring (p=none) to full enforcement (p=reject) — without blocking a single legitimate message.

June 16, 2026

Since 2024 Gmail and Yahoo require bulk senders to authenticate with SPF, DKIM and DMARC. Exactly what is demanded, who is affected, how to comply.

June 16, 2026

SPF, DKIM and DMARC are not rivals but three stacked layers. What each one does, why alignment ties them together, and how they stop spoofing.

June 16, 2026

DMARC aggregate reports are the map to enforcement. What's inside the XML, how to read it, and how daily reports turn into a path to p=reject.

June 16, 2026

A plain-English guide to DMARC: what it is, how it builds on SPF and DKIM, what the policies mean, and what DMARCbis (RFC 9989) changes in 2026.

June 15, 2026

DKIM (RFC 6376) explained: the cryptographic signature, the DNS record, selectors, rotation, 1024 vs 2048 bits, and why DMARC is still needed.