Most cold emails get ignored because they sound like every other generic pitch. But 7 out of 10 salespeople still use the same two-line formula they learned from YouTube. If you're writing cold emails manually, you're leaving replies on the table. Claude can generate personalized, research-backed outreach in seconds—if you ask the right way. This guide shows you exactly how to prompt Claude for cold emails that actually get responses.
The Research Prompt: Find Leverage Before You Write
Before you send anything, you need leverage—a real reason someone should care about your message. Use Claude to dig into a prospect's company, recent moves, and pain points.
Prompt structure:
"Analyze [prospect company] and tell me: (1) What industry shift affects them most right now? (2) What revenue problem could this create? (3) What one thing in their LinkedIn activity suggests they care about this?"
Paste their last 3 LinkedIn posts or a snippet from their website. Claude will surface specific angles you can hook into. Instead of "I think you'd benefit," you now say "I noticed you just hired 5 engineers for your API team—most teams hit scaling problems around month 3." This isn't generic. This works.
The Personalization Prompt: Warm Copy at Scale
Once you have angle, write the email body with Claude instead of staring at a blank screen.
Prompt structure:
"Write a cold email subject line + body for [prospect name] at [company]. They [specific fact about their role/company]. The angle is [your research insight]. The ask is [what you want them to do]. Style: direct, two paragraphs max, no fluff. Tone: helpful expert, not salesy."
Example: "Write a cold email for Sarah Chen at TechFlow. She leads product ops. The angle is they just doubled their user base and ops teams typically become bottlenecks. The ask is a 15-min call to discuss where ops breaks first."
Claude will generate 3-4 versions. Pick the one that sounds most like you, tweak one line, and send it. You'll notice faster response rates because the personalization reads genuine.
The Follow-Up Prompt: Timing Without Desperation
First emails sit in inboxes. Follow-ups get read. But most people either ghost or send "Just checking in" (garbage).
Prompt structure:
"I sent [prospect] an email about [topic] 5 days ago with no reply. Write a follow-up that: (1) Adds new information they don't have (2) References my first email lightly (3) Gives them an easy out. Tone: respectful, concise."
Claude treats this like a separate campaign, not a repeat. The follow-up includes a fresh angle—maybe new proof, a relevant case, or a smaller ask (watch a 2-minute demo instead of a call). It reads like context, not desperation. This is why follow-ups outperform first emails by 20-40%.
The A/B Test Prompt: Test Subject Lines and Hooks
Subject lines determine open rates. Bodies determine reply rates. Test both.
Prompt structure:
"Generate 5 subject lines for a cold email about [offer] to [role]. Constraints: max 50 chars, no emojis or caps, invoke curiosity or urgency. Then, for each subject, write one sentence that hooks that angle."
Example: If you sell API monitoring, Claude might generate subjects like "Your API goes dark—they don't tell you" or "The 3-second window (why most teams miss it)" or "Read: APIs and SLAs—what your users won't forgive."
Track which subjects and first lines get the highest open and reply rates. After 50 emails, patterns emerge. Lean into what works. This turns cold email from art into repeatable math.
FAQ
Can Claude write a cold email that doesn't sound like an AI wrote it?
Yes, but only if you give it a personality to match. Include your actual tone in the prompt—"sound like a technical founder" or "conversational and direct." Claude mirrors what you model. If your prompt is stiff, the output is stiff. If you give it your voice, it learns it. The best emails read like a real person, fast.
How do I avoid Claude cold emails triggering spam filters?
Spam filters flag links, excess capitalization, and common salesy phrases. In your prompt, tell Claude to skip those: "Avoid these: 'proven,' 'revolutionary,' 'don't miss out,' external links." Keep emails under 150 words. Use simple language. Test with one email before sending 100. Warm introductions also help—Claude can help you write those too.
Should I use Claude for subject lines, body, or both?
Both, but start with subject lines. They determine if the email gets opened. Once you have a subject line you like, prompt Claude for the body that matches that angle. This order keeps the email coherent. You can grab the sidera-prompt-pack-v1-en which includes templates for all three, pre-tuned for B2B cold outreach.
How many follow-ups should I send before moving on?
Research shows 2-3 follow-ups across 2-3 weeks hits the sweet spot. After 3 weeks with no reply, they're likely not interested. Claude can help you write the second follow-up differently—add proof, change the ask, switch angles—so it doesn't feel repetitive.
Can I use these prompts for email sequences?
Absolutely. Prompt Claude to write an entire sequence: "Write a 4-email sequence for a [product] prospect. Email 1: hook and angle. Email 2 (day 3): new proof or case. Email 3 (day 7): smaller ask or demo. Email 4 (day 12): final check-in with easy out." This gives you a full campaign framework you can personalize and send.