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SPF, DKIM, DMARC — What They Actually Do and How to Break Them

Not just definitions — a practical look at how email authentication works at the packet level, and what happens when each record is misconfigured.

2026-06-2010 min read

Coming Soon

This post is currently in the research phase.

What it will cover:

→Deep dive into each authentication protocol at the packet level
→What happens when SPF has too many DNS lookups (the include limit)
→DKIM signature failures: replay attacks, key rotation, and selector management
→DMARC policy escalation from none → quarantine → reject
→Building a lab to test each misconfiguration and observing the results
→Real-world spoofing techniques and how these protocols prevent (or fail to prevent) them

Follow @0xvince to know when it drops.