I tested GPT-6 Astra for cold emailing

Hey ColdIQers!

A lot of you told me Codex with GPT-6 Astra now beats Claude Code at building cold email campaigns. So I tested it live on two of my real campaign prompts, from lead list to emails loaded in Instantly.

#1 The people who engaged with my post

I asked it to find the CEOs, founders and sales leaders who engaged with my Claude Code cold email masterclass, then get their emails.

Each of them got an email with two campaign ideas built around what their company does.

#2 Companies hiring GTM people who use coding agents

This time: companies of 30 to 100 people hiring for a GTM or sales role that asks for Claude Code, Codex or another coding agent. The agent went after their CEO or sales leader.

The first line quotes their job ad, then one cold email play built around what they do.

My honest take

I still prefer Claude Code. It's usually better at copywriting, and it would have adapted that first line to each job ad.

But whichever agent you pick, it needs good B2B data. You can use ColdIQ for that and run any campaign on it.

See you on the next one,

Mich

PS: We’re going live with expandi this Thursday (Nov 5, 4 PM CET) to build an outbound campaign from scratch. Join us here.

PS2: Want the GTM skills file I used? It's free, grab it here.