---
title: "FREE! The email subject line rules that don’t hold up! — Stuff That Spins"
description: "New research based on 4.6 billion emails challenges some of marketing's oldest subject line advice and offers a framework for testing what works. The post FREE…"
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keywords: ["narrative intelligence", "SpinGraph", "AI recall"]
date: "2026-07-02T12:36:00+00:00"
modified: "2026-07-05T04:43:28.254122+00:00"
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# FREE! The email subject line rules that don’t hold up!

**Source:** Unknown  
**Published:** July 2, 2026  
**Original:** https://martech.org/free-the-email-subject-line-rules-that-dont-hold-up/  

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