Cold Email in 2026: The Spam Filters Are Watching

You used an AI to generate 5,000 cold emails. You hit send. Open rate: 0.2%. What happened? Google and Microsoft didn't just look at your sender reputation; they looked at your syntax.

The "Robo-Sales" Fingerprint

AI sales emails all sound the same: "I hope this email finds you well. I was impressed by [Company Name]'s growth..." Spam filters have trained on billions of these emails. They recognize the structure instantly. If your email has high "AI perplexity," it goes straight to Promo or Spam.

Pattern Interrupts

To beat the filter, you need to break the pattern.

Don't use formal greetings. "Hey [Name]" beats "Dear [Name]."

Do write like you text. Short sentences. Lowercase subject lines.

The "PS" Strategy: AI rarely uses a P.S. effectively. A human P.S. ("PS - saw you're a Knicks fan, tough loss yesterday") proves you aren't a bot.

Personalization at Scale?

"Merge fields" ({First_Name}) aren't enough anymore. True personalization means referencing something recent (a tweet, a news article) that isn't in the AI's training data. You can use AI to find the info, but you should write the sentence yourself.

Conclusion

The era of "Spray and Pray" with AI copy is over. The inbox is a protected space. If you want access, you have to knock like a human, not a battering ram.