250M+ cold emails analyzed, here's what works.

Coming from:

Lavender AI

28M emails

Gong

85M emails

leadarc.io

20M emails

lemlist

58.2M emails

Snov.io

44M emails

Salesloft

15M emails

If you don’t know me, I’m Leon, the co-founder of leadarc.io. We work with B2B companies to get them more qualified sales calls on a performance basis, meaning they only pay us per meeting held. We send anywhere between 50k — 1M+ cold emails per month for them and have our SDRs call all the replies to vet them.

Book a call here.

In this article:

• Subject lines
• Length, readability and formatting
• Opening
• CTA and sign-off
• Personalization
• Tone and words to avoid
• Follow-ups
• Lists, timing and deliverability

Subject lines

1. Keep it to 1-4 words, since going from 2 to 4 words costs replies (-17.5% replies)
2. Make it look like an internal email or to-do item with no pitch (2x opens)
3. Never ask a question in the subject (Gong -4%, Lavender -56%, Salesloft -17% replies)
4. No numbers in the subject (Gong -9%, Lavender -46% opens, Salesloft up to -73% replies)
5. Keep "AI" out of the subject (-18% opens)
6. Keep social proof out of the subject (-4% opens)
7. Skip salesy words, verbs, superlatives, buzzwords and urgency like "now" or "limited" (up to -17.9% opens, up to -49% replies)
8. Don't leave the subject empty (+30% opens but -12% replies)
9. Skip punctuation like "?" and "!" (-36% opens)
10. Leave their first name out (-12% replies)
11. Name your own company in the subject instead (+68% replies) (Only works for big brands)
12. If someone referred you, say so in the subject (+536% replies)
13. Use "Congrats" when you have something real to congratulate (+100% replies)
14. Try "Hello" as the whole subject (+243% replies)
15. Be direct with words like "advice", "call" or "meet" (+36% replies)
16. Keep the tone neutral, since overly positive or negative subjects hurt (up to -34% replies)
17. Don't offer content or data in the subject (up to -63% replies)
18. Leave out "you" and "your" (up to -14% replies)
19. Stay at 31-50 characters and never pass 70 (best replies in every region)

Length, readability and formatting

1. Aim for 25-50 words in 3-4 sentences, never over 100 (+65% replies)
2. Make it readable on a phone without scrolling (+83% replies)
3. Use 1-2 sentence paragraphs with lots of white space
4. Write at a 3rd-5th grade reading level (+67% replies)
5. Skip bullet points, and use dashes if you really need a list (bullets -37% replies)
6. Use as few links as possible
7. Don't attach files (+60% bounces)
8. Leave images out when emailing North America (-89% replies)

Opening

1. Open with an observation about them, and double-check that it's true
2. Turn your research into a guess about their problem
3. Lead with their priorities and problems (+20% replies)
4. Don't pitch your product (up to -57% replies)
5. Write about "you", not "I"
6. Open with "Hope all is well" (+24% meetings)
7. Cut "I hope this finds you well", since it wastes your preview text
8. Greet with "Hey {first name}" (+23% replies, "Hello" -9%)

CTA and sign-off

1. Ask if they're interested instead of asking for their time (2x meetings)
2. Offer something useful instead of a meeting (+28% replies) (Depends on offer)
3. Make only one ask, with one question at most (4 questions: -39% replies)
4. Ask an easy question, not an open-ended one
5. Don't end on "thoughts?" (-20% meetings)
6. Leave out ROI claims (-15% meetings)
7. Sign off with "Best" (+9.8% replies, "Thank you" -30.7%)
8. On personalized emails, drop the opt-out line where that's legal (-38% replies with it)

Personalization

1. Personalize every cold email (Gong up to 5x, Lavender 2x replies)
2. Mention actions their company has already taken (3x replies and meetings)
3. For directors and above, personalize to their company (3x replies)
4. For non-managers, personalize to the person (2x replies)
5. Name a challenge specific to their industry (+88% replies)
6. Use a customer story from a similar company with a similar problem (+41% replies)
7. Pitch execs on revenue, cost or risk, since they reply less (-30% replies)
8. Skip where they went to school
9. Add a personal P.S. (+35% replies)
10. Personalize about 20-25% of the email, like the first and last sentence (2x replies)
11. Don't rely on {first name} variables alone, they did worse than no personalization (0.81% vs 1.82% replies)
12. Write 3-5 versions of each line with spin syntax (about 2x replies vs variables only)

Tone and words to avoid

1. Sound unsure with words like "might" or "seems" (+35% replies)
2. Write casually, like a text, since formality cuts replies
3. Drop "did you know" stats, because informative tones hurt replies
4. Cut buzzwords and jargon like "AI" and "platform" from the body
5. Never write "I never heard back" (-14% meetings)
6. Don't mention that you called or left a voicemail
7. Avoid spammy words like "free trial" or "investment opportunity" (2.2x bounces)

Follow-ups

1. Keep follow-ups to 1-2 sentences (2x replies)
2. Send a breakup email (+89% replies, breakup words in the subject +30%)
3. Don't offer case studies in follow-ups (up to -47% replies)
4. Once they reply, ask 2-4 questions (+25-50% replies)
5. Email everyone twice before recycling (65% of positive replies come from the first email)
6. Send at least one follow-up (more total replies, fewer bounces and unsubscribes)

Lists, timing and deliverability

1. Keep each campaign to 10-50 leads (2.7x replies vs 500+)
2. Turn off open tracking (2.2x replies)
3. Don't track links (4x replies without)
4. Plan your biggest push for January, the yearly high
5. Send Monday morning if you can, never on weekends (+25% vs up to -71% replies)