Does cold email still work in 2026?
Yes, for small lists of people with a clear reason to hear from you. Instantly's Cold Email Benchmark Report 2026, built from emails sent on its platform between 1 January and 18 December 2025, puts the average reply rate at 3.43%. The top 25% of campaigns reach 5.5% or more and the top 10% reach 10.7% or more. Instantly says reply rates held steady even as sending volume grew, and credits relevance for it. That is a vendor's reading of its own data.
The report's own description of each tier shows what separates them:
| Tier (Instantly, 2025 data) | Reply rate | How Instantly describes the senders |
|---|---|---|
| Top 10% | 10.7% or more | Micro-segmentation, continuous A/B testing, smart automation |
| Top 25% | 5.5% or more | Targeted lead lists, segmentation and message personalisation |
| Average | 3.43% | Healthy inbox placement and volume, but lacking targeting precision and messaging refinement |
Instantly's reply rate counts all replies, including replies to follow-ups and "no thanks", divided by all emails sent. Our comparison of cold email reply rate benchmarks explains why positive replies per 100 people is the better number to track.
Buyers avoid the rest. Gartner's survey of 632 B2B buyers, run in August and September 2024 and published on 25 June 2025, found that 73% actively avoid suppliers who send irrelevant outreach.
What changed in the inbox since 2024?
Gmail and Outlook.com now publish rules for senders, and both tighten at 5,000 messages a day. Gmail's email sender guidelines have applied to everyone sending to Gmail accounts since 1 February 2024. Microsoft announced requirements for high-volume senders to Outlook.com consumer addresses on 2 April 2025.
| Rule | Gmail (personal accounts) | Outlook.com (consumer addresses) |
|---|---|---|
| Applies to | All senders from 1 Feb 2024; extra rules above 5,000 messages a day | Domains sending over 5,000 emails a day |
| Authentication | SPF or DKIM for all; SPF, DKIM and DMARC for bulk senders | SPF, DKIM and DMARC |
| Spam reports | Keep below 0.10% and never reach 0.30% (Postmaster Tools) | Not set as a number in the announcement |
| Unsubscribe | One-click unsubscribe for marketing and subscribed messages from bulk senders | Recommended: a functional, clearly visible unsubscribe link, particularly for marketing or bulk mail |
| What happens if you miss | Rate limiting, blocking or messages marked as spam | Rejected with error 550 5.7.515 from 5 May 2025, per Microsoft's 29 April update; an older paragraph on the page still says Junk first |
A founder sending 30 cold emails a day is far below 5,000, but the all-sender rules still apply to any of them going to personal Gmail addresses. Google's sender guidelines FAQ says they don't apply to mail sent to Google Workspace accounts, where many B2B buyers are. Our fix list for cold emails going to spam walks through the DNS records.
How much room does a 0.1% spam rate leave?
Very little, and less the fewer emails you send. Google's Postmaster Tools help page defines the spam rate as the percent of your messages delivered to an engaged recipient's inbox and then marked as spam. Here is what Google's two thresholds mean in reports per day; our spam fix list above covers what one report does at founder volumes. The arithmetic is ours.
| Emails reaching personal Gmail inboxes a day | Reports at 0.10% | Reports at 0.30% | What one report does |
|---|---|---|---|
| 100 | 0.1 | 0.3 | 1.0% for that day |
| 500 | 0.5 | 1.5 | 0.2% |
| 1,000 | 1 | 3 | 0.1% |
| 5,000 | 5 | 15 | 0.02% |
Two caveats from the same page. Postmaster Tools covers mail to personal Gmail accounts, so recipients on company domains don't show up there. And on low-volume days its dashboards may not include all data. So the table applies only to the share of your list on @gmail.com or @googlemail.com addresses. Within that share, 500 emails a day with one report is already 0.2%, twice Google's 0.10% guidance, so who you send to matters more than how many.
What do founders and recipients say in recent threads?
Across five threads from 2018 to 2026, the pattern is the same: recipients say they delete generic or obviously machine-written email, and senders who say it still works describe small, carefully chosen lists. Each line is one person's experience.
- Recipients spot AI drafts. In the Hacker News discussion of Zach Holman's July 2026 essay The Cold Email (126 comments when checked on 24 October 2026), one commenter who reads a dozen inbound cold emails a day said the model-written ones are instantly obvious, and asked senders: "Please use models to research people and learn about them. But please write the email yourself."
- Volume changed the recipient's habits. Another commenter in that thread said people replied when cold emails came once every three months, and now dozens a day go straight to the bin. A third said that if the one-line preview in the inbox list gives no reason, the email goes to the trash.
- The writer has to care. Holman, the second engineer hired at GitHub and now the founder of Signed, wrote that good cold outreach means being interested in the other person and genuine, and that with virtually all the cold outreach Holman gets, it's possible to see whether the sender is trying to play them.
- Hand-written still isn't magic. In a 2018 Ask HN on whether cold emails still work (9 comments), one commenter selling a developer product hand-wrote more than 100 emails to very relevant people and reported an open rate around 70% but a single-digit response rate.
- Targeting comes up every time. In a November 2025 r/SaaS thread (about 20 comments when checked on 24 October 2026), several commenters said it works only with tight targeting, smaller lists and lower volume; one said it's dead. In a March 2025 r/SaaS thread (8 comments), one commenter's advice was simply to send fewer emails.
- Claims without numbers get challenged. In a September 2026 r/SaaS thread titled "cold email is not dead" (about 44 comments), the poster showed a Stripe screenshot after one email to a list of SaaS companies. Commenters asked for metrics, and one wrote: "Open rate, reply rate, positive replies, meetings booked, and how many bounced. Otherwise it's just a Stripe screenshot." The poster declined to share the full numbers, but said in replies that they had scraped 6,000 to 7,000 websites, ended up with about 3,500 addresses, and found many were dead and bounced.
What does a cold email that still works look like?
It goes to someone with a recent, visible reason, says that reason in the first line and asks one question. Instantly's report recommends micro-segmented lists, a first email under 80 words with a single call to action, and timing based on buyer signals such as hiring, funding, product launches and website visits.
| Blast | Signal-led | |
|---|---|---|
| List | Thousands from a database or scrape | Dozens a week, each with a reason |
| First line | About you or a compliment | The reason: their post, job ad, launch or funding |
| Ask | A 30-minute call | One question they can answer in a line |
| Length | Several paragraphs | Under 80 words |
| Who wrote it | A template or a model, unread | You, or a draft you checked against their profile |
A copyable version, 60 words:
Job ads are one of the easiest signals to find for free; our guide to using job postings as buying signals has more templates.
Should you let AI write your cold emails?
Let AI do the research and the list work, and make sure every email reads like one person wrote it to another. The Hacker News commenter above drew the same line: models for research, a human for the words. If you use AI drafts, check them against the person's profile and cut anything you wouldn't say out loud. Our guide to whether prospects can tell an email was written by AI lists the tells.
Siela's AI SDR treats daily goals as targets, not quotas, and does not pad the list. Every lead gets a one-line reason, and with Hot leads selected it only contacts leads it scores hot. It finds and verifies each person's work email and emails only deliverable addresses. The first email is your own template with each person's name, company and title filled in, sent up to 150 a day per Gmail mailbox, 2 to 5 minutes apart, with AI follow-ups in the same thread.
What should you test this month?
Run one small, measured test before you decide cold email doesn't work for you.
Check authentication first
SPF and DKIM on your sending domain at minimum, plus DMARC. Gmail requires SPF or DKIM from every sender.
Pick 100 people with a signal
A job ad, a post about the problem, a launch or a funding round in the last 30 days. Verify every address before sending.
Write the first email yourself
Under 80 words, the reason in line one, one question. Start from our cold email templates if you're stuck.
Send 20 a day, follow up twice
Five working days gets you through the list. Stop after the second follow-up.
Count what matters
Positive replies and meetings per 100 people, bounces and any spam complaints. At Instantly's 2025 average of 3.43% replies per email sent, 100 people and 300 emails would bring about 10 replies of any kind.
Frequently asked questions
Is cold email dead because of AI-written spam?
No, but generic email is getting ignored faster. Instantly's 2026 benchmark, covering emails sent in 2025, puts the average reply rate at 3.43% and the top 10% of campaigns above 10.7%. Recipients in 2026 Hacker News discussions said they delete obviously machine-written emails, so the gap is between researched emails written for one person and bulk drafts nobody checked.
Do Gmail's sender rules apply if I only send a few cold emails a day?
Some do. Google's sender guidelines require every sender to Gmail accounts to set up SPF or DKIM, use valid DNS records and TLS, and keep spam rates in Postmaster Tools below 0.3%. The stricter rules, including DMARC and one-click unsubscribe for marketing messages, apply to senders of more than 5,000 messages a day.
Why do small cold email lists still get spam complaints?
Spam rate is a percentage, so a small list has less room for error. At 100 emails a day reaching Gmail inboxes, a single spam report is 1% for that day, ten times Google's 0.10% guidance. Choosing people with a clear reason to hear from you is the only reliable way to keep reports near zero.
Did Microsoft change its rules for cold email senders?
Microsoft announced on 2 April 2025 that domains sending over 5,000 emails a day to Outlook.com consumer addresses must pass SPF, DKIM and DMARC, with enforcement from 5 May 2025. A 29 April update says failing messages will be rejected with error 550 5.7.515, though an older paragraph on the same page still says Junk first. The announcement covers hotmail.com, live.com and outlook.com addresses.
What should I measure to know whether cold email works for me?
Count positive replies and booked meetings per 100 people contacted, plus bounces and spam complaints. Open rates are a weak signal: Google's email sender guidelines say Google doesn't track open rates and can't verify the accuracy of open rates reported by third parties. Run at least 100 people with a clear signal before judging.
Sources
- Instantly: Cold Email Benchmark Report 2026 (updated 12 Jan 2026)
- Google Workspace Admin Help: Email sender guidelines (checked 24 Oct 2026)
- Gmail Help: Postmaster Tools dashboards (checked 24 Oct 2026)
- Microsoft Defender for Office 365 Blog: Outlook's new requirements for high-volume senders (2 Apr 2025, updated 30 Apr 2025)
- Gartner: Sales survey finds 61% of B2B buyers prefer a rep-free buying experience (25 Jun 2025)
- Hacker News: The Cold Email (discussion) (29 Jul 2026)
- Zach Holman: The Cold Email (29 Jul 2026)
- Hacker News: Ask HN: Do cold emails still work? (3 Jul 2018)
- Reddit r/SaaS: Be honest, does cold email still work in 2025? (22 Nov 2025)
- Reddit r/SaaS: Does Cold Email Still Work in 2025? (6 Mar 2025)
- Reddit r/SaaS: cold email is not dead, i just proved it to myself (19 Sep 2026)
- Gmail Help: Email sender guidelines FAQ (checked 24 Oct 2026)