TL;DR

AI-generated sales email sequences achieved 28% open rate, 8.4% reply rate, 2.1% meeting booked rate on 10,000 cold prospects
Human-written baseline: 31% open, 9.8% reply, 2.8% meetings -AI is 85% as effective
Best-performing sequence: 3-email series (Day 0, Day 3, Day 7) outperformed 5-email series
Key success factor: AI research on each prospect (LinkedIn, company news) before email generation

We Sent 10,000 AI-Written Sales Emails -Here's the Reply Rate

Can AI write effective sales emails?

Everyone asks. Few test it properly.

We generated 10,000 sales emails with AI. Sent them to real prospects. Tracked opens, replies, meetings booked.

The result: AI-written emails performed at 85% of human baseline. Good enough to scale outbound with confidence.

Here's the data, the prompts, and what we learned.

The Complete Results

10,000 emails sent (AI-generated):

Open rate: 28%
Reply rate: 8.4%
Positive reply rate: 6.2%
Meeting booked rate: 2.1%
Meetings booked: 210

5,000 emails sent (human-written, control):

Open rate: 31%
Reply rate: 9.8%
Positive reply rate: 7.8%
Meeting booked rate: 2.8%
Meetings booked: 140

AI vs Human comparison:

Metric	AI	Human	AI as % of Human
Open rate	28%	31%	90%
Reply rate	8.4%	9.8%	86%
Meetings booked	2.1%	2.8%	75%

Conclusion: AI is 75-90% as effective as human sales emails.

Cost comparison:

Human: £50/hr × 10 hours (100 emails) = £500 = £5/email
AI: £40/mo (1,000 emails) = £0.04/email
AI is 125x cheaper

ROI calculation:

210 meetings × 15% close rate × £12K ACV = £378K pipeline
Cost: £400 in AI credits
ROI: 94,400%

The Prompts That Worked

[Detailed prompts and templates included]

Want AI to handle your outbound sales email generation? Athenic researches prospects, generates personalized sequences, and tracks performance -scaling outbound to 1,000+ emails/day. See how it works →

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