RFC Ignorant

A small static reference site on protocol hygiene and mail operations, with historical context around the former RFC-Ignorant DNSBL.

Purpose

RFC Ignorant is a lightweight notebook that collects lessons from running and operating mail infrastructure. It highlights the operational guardrails that tend to fail first: working abuse and postmaster contacts, reasonable DNS data, and predictable SMTP behavior.

The original RFC-Ignorant.org DNSBL tried to publish public lists of domains with broken contact processes. That list is long gone, but the operational expectations it documented still shape how modern providers triage abuse.

History snapshot

RFC-Ignorant.org was once a DNS-based blocklist that attempted to list domains deemed non-compliant with expected RFC behavior. Reports around 2012 cited aging hardware and a shift toward a handful of dominant email providers as reasons the service faded. A successor under rfc-ignorant.de was discussed but never evolved into a permanent DNSBL.

How this site works

This site is intentionally steady: plain HTML, one stylesheet, and content that favors context over drama. It is published by Kernel-Error as a static archive so operators can keep a reference copy offline if needed.

For technical background on HTTPS, TLS, and transport security, see kernel-error.dev.

No ads, no tracking, no analytics. This site is static.

This site does not operate any DNS blacklist (DNSBL/RBL).

Start exploring

Read the history of RFC-Ignorant.org.
Review how to build RBL and RHSBL lookups in Postfix.
Check the guide on why some mail systems require STARTTLS.
Audit postmaster@ and abuse@ mailboxes.
Deep-dive into DANE/TLSA deployment or TLS cipher suites.