How many people should you contact before giving up on a channel?
About 3 divided by the reply rate you expect, counted in people, not emails. If each person replies independently at rate p, the chance of zero replies from n people is (1 − p) raised to the power n. Set that to 5% and n comes out at roughly 3 ÷ p. It is the rule of three from statistics used in reverse: zero events in n tries puts the true rate below 3/n with 95% confidence. We worked out what that means for the reply rates people actually report:
| Reply rate you expect | Where the figure comes from | People for a 95% chance of at least one reply | Chance of zero from 50 people | Chance of zero from 150 |
|---|---|---|---|---|
| 0.74% per contact | Smartlead's median sender | 404 | 69% | 33% |
| 2.63% per contact | Smartlead's top 10% of senders | 113 | 26% | 1.8% |
| 6.2% per recipient | Hunter, sequences of 21 to 50 recipients | 47 | 4.1% | under 0.1% |
| 1 in 15 | One founder's low end for title-matched lists | 44 | 3.2% | under 0.1% |
| 1 in 5 | Same founder's low end for people who had voiced the pain | 14 | under 0.1% | under 0.1% |
Read the first row carefully. A sender performing exactly at Smartlead's median, which counts replies per contact across more than 850 million emails, gets no reply at all from 50 people 69% of the time. Zero from 50 on a broad list tells you almost nothing. Zero from 50 people who posted about your problem would be a real result. The calculation assumes everyone replies independently at the same rate, which real lists don't quite do, so treat the counts as minimums.
Why do people who showed the pain change the numbers?
Because a higher expected rate shrinks the sample you need to learn anything. Nir Shub, a founder writing on Indie Hackers in January 2022, reported typical reply rates of 1 in 3 to 1 in 5 from people who had expressed the pain, mostly found in Facebook groups and Reddit, against 1 in 10 to 1 in 15 from lists built in Sales Navigator or Apollo. The explanation offered: a perfect title match may have a dozen more urgent problems right now. Those are one founder's figures from experience, not a study. The gap between the two groups matters more than the exact numbers.
Here is what it does to a small test. Say you can contact 150 people over three weeks.
- Broad list at the 0.74% median: 150 × 0.0074 = about 1 reply expected. You can't compare anything, and a third of the time you get none.
- Three segments of 50 people who posted the problem, at 1 in 5: about 10 replies expected per segment. Now you can see which segment is worth more of your time.
Jed Mahrle, who runs the Practical Prospecting newsletter and an outbound agency, makes a related point in a 19 April 2026 issue: with fewer than 10,000 reachable contacts, go the targeted route, with tighter targeting, higher intent signals and more research per send. Mahrle adds that the honest top agencies publicly say 1 to 3% reply rates for automated cold email at scale are, in most cases, as good as it gets. Hunter's 2026 report, on emails its users sent in 2025, points the same way: sequences with 21 to 50 recipients replied at 6.2%, against 2.4% for sequences of more than 500. To find the high-rate people in the first place, see our guide to finding people with the problem you solve.
What should you check before you blame the channel?
Deliverability first, then the message, then the targeting. Mahrle's three phases of a cold email campaign (19 October 2025) give the order. When nothing comes back at all, not even "no thanks" or "unsubscribe", Mahrle says nine times out of ten it is deliverability.
| What you see | What it usually means | What to do next |
|---|---|---|
| Nothing at all, not even a no | Emails may be landing in spam or not arriving | Run a placement test, check bounces and spam complaints, then simplify to a soft ask |
| Only "no thanks" or "not interested", no reasons | Delivered, but the message isn't landing | Test the problem, the value and the call to action one at a time; Mahrle uses about 500 emails per variation |
| No's with reasons ("We already use X", "We're too small") | Close: the reasons are data | Change targeting or positioning to match what they told you |
| Replies, but no meetings | The offer or the next step is too big | Ask a yes-or-no question before you ask for a call |
Two numbers to watch while you do this. Google's email sender guidelines tell senders to keep spam rates reported in Postmaster Tools below 0.3%. Instantly's 2026 benchmark report advises keeping bounce rates below 2%; Hunter measured an average of 3.6% across its users in 2025. The last row describes a February 2026 r/coldemail thread: 40 to 50% opens, about 2% replies and zero meetings, where one commenter said zero meetings "screams weak or misaligned offer". Our checklist for cold emails going to spam covers the first row in detail.
What do the 'zero replies' posts actually show?
Most of them are too small to judge, and the rest point at the setup before the channel. Five 2026 posts, with the arithmetic run on each:
| Post | Reported | What the arithmetic says |
|---|---|---|
| r/coldemail, May 2026 | About 120 emails to about 40 leads, three emails each; no replies except 2 out-of-office | That is 40 people. Even at Smartlead's top-10% rate, zero from 40 happens about 34% of the time. Too few to judge. |
| r/SaaS, August 2026 | 300 cold emails over 25 days, no replies | If that was 300 different people, a median sender would see zero only about 11% of the time. Worth checking deliverability before rewriting anything. |
| Indie Hackers, April 2026 | 342 emails, 0 replies; 2,000 more queued until Gmail was restored | The founder was waiting for Gmail to be restored, so check the sending account before blaming the channel. |
| Indie Hackers, October 2026 | About 45 hand-written emails: 0 interested. About 611 through a tool: about a dozen replies, 2 interested, both small skincare brands | 45 is too few to compare with 611. The useful result was the segment: both interested leads came from one niche. |
| Indie Hackers, July 2026 | 43 emails to local businesses picked because their sites visibly needed help; 17 replies, 1 client at $230 a month | At roughly 40%, 43 people is plenty. Self-reported by a founder who sells a prospecting tool. |
In the first thread, one commenter put the counting rule in one line: "You should count %reply relative to leads not total emails send." The 650-email founder shows the other lesson. The sample that looked like a failure contained a segment that showed interest.
How to run a fair test of a channel
Size the test to the reply rate you expect, fix deliverability before you send, and change one thing at a time.
Pick one segment and one reason to write
One type of company, one role, one signal such as a post about the problem or a job ad. Comparing segments is covered in our guide to defining an ICP before you have customers.
Size it with 3 ÷ expected rate
About 400 people for a broad list at the median, about 50 for a tight segment like Hunter's best, about 15 for people who voiced the pain.
Check the plumbing
Send to your own Gmail and Outlook addresses, verify every address, and watch bounces and spam complaints.
Send in small daily batches
Spread the sample over two weeks so one bad day doesn't decide the result.
Count per person
People contacted, replies, positive replies, meetings. Write down which row of the table above you are in.
Apply a stopping rule
Our rule: reach the full sample with clean deliverability and zero positive replies, then change the segment or the offer. Drop the channel only after two or three segments fail at full size.
If you would rather start from people with a reason to reply, Siela's AI SDR contacts only leads it scores hot when Hot leads is selected, verifies each work email and emails only deliverable addresses. Its daily goals are targets, not quotas, so it doesn't pad a thin list to hit a number.
Frequently asked questions
Is 100 cold emails enough to know if cold email works?
Not for a broad list. At Smartlead's median of 0.74% replies per contact, 100 different people produce zero replies about 48% of the time, so silence is close to a coin flip. For people who have posted about the problem you solve, where one founder reported 1 reply in 3 to 5, 100 is far more than you need. Count people, not emails.
What does it mean when nobody replies, not even to say no?
Usually that your emails aren't arriving. Jed Mahrle of Practical Prospecting says total silence is a deliverability issue nine times out of ten. Test inbox placement, check your bounce rate and spam complaints, and simplify to a soft ask. Only after that should you start rewriting the copy or changing the list.
How many emails should each test variation get?
It depends on your expected reply rate. Jed Mahrle usually sends about 500 emails per variation and says there is no strict rule. By our 3-divided-by-rate rule, 500 people suits a reply rate of about 0.6%. For a tight segment replying at around 6%, about 50 people per variation is enough to see whether it gets replies. Change one element at a time: the problem, the value or the ask.
When should you switch from cold email to another channel?
Only after a fair test has failed more than once. Our rule is to reach the full sample for your expected rate with clean deliverability, then change the segment or offer if you still get no positive replies. Drop the channel after two or three segments fail at full size. A new channel won't fix an offer nobody wants.
Sources
- Smartlead: What is a good cold email response rate? (checked 24 Oct 2026)
- Hunter: The State of Email Outreach 2026 (checked 24 Oct 2026)
- Belkins: What are B2B cold email response rates? (2026 study) (updated 26 Jun 2026)
- Instantly: Cold Email Benchmark Report 2026 (updated 12 Jan 2026)
- Jed Mahrle, Practical Prospecting #129: The 3 Phases of Every Cold Email Campaign (19 Oct 2025)
- Jed Mahrle, Practical Prospecting #145: Why You Should Send More Emails (19 Apr 2026)
- Google Workspace Admin Help: Email sender guidelines (checked 24 Oct 2026)
- Wikipedia: Rule of three (statistics) (checked 24 Oct 2026)
- Indie Hackers: No one is replying to my cold outreach, should I keep trying? (20 Jan 2022)
- Indie Hackers: 650 cold emails, 2 interested leads, 0 customers (so far) (7 Oct 2026)
- Indie Hackers: I sent 43 cold emails with my own tool. 17 replied. 1 paid. (15 Jul 2026)
- Indie Hackers: Cold email got me zero replies but content marketing got me real conversations (1 Apr 2026)
- r/coldemail: Nearly 120 emails sent and no replies (5 May 2026)
- r/SaaS: 300 cold emails sent but no replies (9 Aug 2026)
- r/coldemail: Cold emails getting decent open rates but no replies, what am I doing wrong? (23 Feb 2026)