Jimmy KimCEO & Founder, Commerce Roundtable · Marketer of 17+ Years, 4x Founder. Former DTC/Retailer & SaaS Founder. Newsletter. Host of ASOM & Send it! Podcast. DTC Event: Commerce Roundtable

How to Use Claude AI to Write Email Subject Lines That Convert

16 May 2026 · 1 min

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1:15

In this tutorial segment, the presenter explains how to prompt Claude AI to generate effective email subject lines for a brand, using Diamond Apparel as a concrete example. The speaker outlines a prompt structure that specifies the target audience (e.g., summer‑essential shoppers), requests a mix of four persuasive angles—curiosity, urgency, social proof, and benefit—and imposes practical constraints such as keeping lines under 50 characters and avoiding clickbait. Sample subject lines illustrate each angle. The presenter emphasizes an iterative workflow: repeatedly refining prompts, reviewing Claude’s output, and rewriting as needed. Over time, this process builds a rich chat history and a reusable library, turning Claude into a powerful, time‑saving asset for marketers and their teams.

Chapters

How do you generate subject lines that are relevant and interesting and on brand? What you're gonna have to do is we're gonna focus on, let's say, summer essentials. That's like coming up when you're watching this this summer. You're gonna come up with a prompt that basically says, hey, gimme 10 subject lines again for my brand, Diamond Apparel, who focuses on this audience. I want a mix of curiosity, urgency, social proof, benefit. So subject lines don't get cut off by Yahoo, Gmail, et cetera. Keep 'em under 50 characters and no clickbait. And here's just like a sample. Your closet got quieter. Summer essentials last 48 hours, and you can see what angle they're playing to. The 10,000 or 12,000 that you asked for. Social proof. Built for the office, made for the weekend is the benefit. What our customers wear after work is curiosity. And then urgency. If you're doing a Drops Friday, gone by Sunday. This is kind of something you'll get back. You'll get back a table or different types of ones. Again, I don't like this. Change that. Rewrite 'em yourself. Subject line should look like this. The more back and forth that you do with the AI and the more prompting and the more robust these prompts are, the better. But again, subject line prompts. Here's the overview, here's the workflow, um, and here's the prompt itself. So copy that, fill this out, get it going. It will do 80, 90% of the work. You keep training and building it, and over time you've got a really rich chat history and library where Claude is going to be really, really great asset for you and/or your team.