Cold email people answer.

Two things changed. Gmail, Yahoo and Outlook now publish hard rules for senders, with numbers attached ^{8 9 10}. And AI made generic email cheap to write, so readers and their software are getting better at spotting it. Max Kolysh, a YC Visiting Partner, says long emails get ignored and readers “assume you used an LLM to write it” ⁶. Pete Koomen, a YC partner and Optimizely’s co-founder, gave his own email agent a rule for sales pitches: “...trying to sell me something: archive” ¹¹.

Cold email also isn’t where most first customers come from. Kolysh: “Customers one through three almost always come from your personal network.” ⁶ Epstein calls a warm intro the best outreach hack there is and estimates it converts two to three times better than cold ². Work your network first, and use cold email for the people it can’t reach. Not sure who they are yet? Start with prospecting.

This is the stage YC partners describe, and where I’d start: tens of emails a day, not thousands. Epstein’s rough math says founders need “dozens of emails per day, possibly even 50 per day” to see results ². Christina Gilbert, a YC Visiting Partner who closed millions of dollars in founder-led sales at OneSchema, recommends doing at least your first 100 by hand, so you learn who replies and why ¹. Koomen’s version: “Start by writing each email by hand.” ¹²

• Send from your own work address, with your name in the From line. Epstein: the From “should just be your personal name.” ²
• Turn on SPF and DKIM for your domain and add a basic DMARC record (all three are explained in the next section). Gmail requires every sender to have at least SPF or DKIM ⁸.
• Check every address with a verifier before you send, and keep bounces under 2% ¹³.
• Write each email to one person, about them. No mail merge with the name swapped.
• Plain text, like a note to a colleague. Gustaf Alströmer, a YC partner: “Write your email in plain text only, like you would write it to a friend.” ¹⁴
• Keep a simple sheet: who you emailed, when, what they said, and who asked you to stop.

Your main domain carries your company’s everyday email. Separate sending domains keep its reputation “from being damaged if your emails are marked as spam,” as Clay’s deliverability guide puts it ³. Most of this is an afternoon’s work.

1. 1

   Buy two or three lookalike domains.

   Variations on your name, like tryacme.com or getacme.com, each forwarding to your real site with a permanent (301) redirect, so anyone who checks lands somewhere real ³. Use separate domains, not subdomains: when Gmail decides who’s a bulk sender, it counts all mail from the same main domain together ¹⁵.

2. 2

   Create inboxes in your own name.

   Two or three per domain, on Google Workspace or Microsoft 365. Nick Abraham, who runs the lead-generation agency Leadbird: “Always use Google or Microsoft accounts - most trusted and stable.” ⁴ Smartlead’s data from its own customers agrees: Gmail senders got about twice the replies per contact of custom mail servers (a correlation, not a test) ¹³.

3. 3

   Add the three records.

   SPF is a public list of the servers allowed to send email for your domain. DKIM puts a signature on each email that proves it came from you and wasn’t changed on the way. DMARC tells inboxes what to do when an email fails those checks and sends you reports; start with the monitoring-only setting (p=none). Gmail and Yahoo require all three once you send in bulk ^{8 9}. If DNS settings are new to you, this is the step to get help with.

4. 4

   Connect a sending tool.

   Instantly or Smartlead sends from all your inboxes in turn, schedules follow-ups, stops them when someone replies and gathers the replies in one place. Set each inbox to a low daily number and leave it there.

5. 5

   Send plain text, with nothing tracked.

   Turn off open tracking, and keep links and attachments out of the first email. Abraham: “Plain text-only. No open tracking, links, or attachments. This just ruins deliverability.” ¹⁶

The domain name matters less than people think. Abraham, who says his agency runs more than 125,000 inboxes ⁴, has tested branded against unbranded domains at scale: “Branded domains matter way less than people think.” He says sender names barely matter either ⁷. I’d still send as yourself: it’s honest, it’s what YC partners tell founders to do, and US law requires the From line to identify who sent the email ¹⁷.

Pre-warmed inboxes are fine. A brand-new inbox on a brand-new domain has no sending history, so sending tools usually warm it up first with automated back-and-forth mail. Pre-warmed inboxes come with that history; Zapmail sells them as a way to “Skip 3 to 4 weeks of warmup” ¹⁸. Check three things before you buy:

• Who owns the domain. Instantly says of its pre-warmed accounts: “We currently retain domain ownership and administrator access.” ¹⁹ That’s fine for a test. For anything long-term, I’d want domains I own.
• Whose name is on the inbox. Smartlead’s pre-warmed mailboxes come with “personas already assigned,” and the names can’t be changed ²⁰. Send as yourself, or don’t send.
• How much each one sends. Even vendors who sell them cap it: Instantly recommends at most 20 to 25 emails a day per account ¹⁹. Pick a low number, keep it fixed, and add inboxes when you want more volume instead of pushing one harder.

How many inboxes you need. Count follow-ups too. Say you want to reach 50 new people a day with a first email and two follow-ups. Once it’s running, that’s up to about 150 emails a day. At 15 per inbox, close to the median of 14 in Smartlead’s data ¹³, that’s 10 inboxes: four or five domains with two or three inboxes each, so more domains than the two or three you’d start with. That’s my arithmetic, not a rule.

• Verify every address and keep bounces under 2% ¹³.
• Send catch-all addresses separately, or skip them. These are company mail servers that accept any address, so a checker can’t confirm the person exists ⁴.
• Never buy a list. Google: “Don’t purchase email addresses from other companies.” ⁸
• Keep spam complaints under 0.1%, and never let them reach 0.3%, which is 3 reports per 1,000 emails ⁸.
• A low, fixed number of emails per inbox per day.
• Plain text. No images, attachments or open tracking, and no links in a first email you send at volume.
• An easy way out in every email, like “If this isn’t relevant, tell me and I won’t write again,” honored right away.
• Only people with a real reason to hear from you. Relevance is what keeps complaints down.

Most founders never get near 5,000 a day, so the bulk rules may not strictly apply to you. The rules for every sender do, and one careless campaign can cross 0.3%. Gmail also says it started “ramping up its enforcement on non-compliant traffic” in November 2025 ¹⁵.

Google’s own stance, honestly. Google doesn’t endorse cold email. Its sender guidelines say “Don’t send messages to people who didn’t sign up to get messages from you” ⁸. Google Workspace’s terms ban using it for “unsolicited mass email” ²², and accounts that send spam “might be permanently restricted from sending email” ²³. My read: what survives is mail people don’t mind getting, meaning relevant, one to one and low in volume. That’s the only kind of cold email I’d send anyway.

Gong, which sells sales software, analyzed more than 28 million cold emails and found that “Pitching reduces reply rates by as much as 57%.” ²⁴ Gilbert’s version: executives don’t care that your database is built in Rust; they care about hitting their quarterly target, so she keeps the product explanation to one sentence ¹.

Abraham’s formula: “The best offers have a quantifiable end result, risk reversal, and social proof.” ⁵ In plain words:

Two refinements. A name they know beats a bigger number from a company they don’t, Abraham says ⁷. And for business customers, Gustaf Alströmer would skip the free trial: “Go for a money-back guarantee and go for the ability to opt out instead.” ¹⁴

Size the ask to what you have:

• Nothing to sell yet: ask for advice about how they handle the problem today. Only if it’s true. Kolysh: “If you’re not actually open to learning from them and you’re just trying to disguise a sales call, don’t do this.” ⁶
• A product, no customers: offer something useful first, like a short audit or a finding about their business, then ask for 15 minutes. Kolysh calls 20 minutes of work before asking for someone’s time “quite a reasonable trade.” ⁶
• A few customers: the full offer, with a result, less risk and a name they know, and a 15-minute call.

The smoothie-party rewrite. Aaron Epstein shows this with a YC company that sold office smoothies. Its first email was about the founders: they were in the YC batch, hustling to hit their Demo Day goal, and asked to be forwarded to the office manager. Epstein: “It’s less clear what’s in it for the recipient.” The rewrite offered the whole team a free smoothie party in return for feedback, and it “helped get them in the door” for long-term deals ². The full email is in the examples below.

1. A short subject about their world. A few words; lowercase is fine. Epstein’s examples: “Hey quick question,” “Can I get your advice,” “Help a fellow founder.” ² For an agent company Gilbert worked with, “broken agents” beat the more descriptive “better agents for every workflow.” ¹
2. Open with them. A fact about their company, not your name and title. The first few words also show as the preview in Gmail ¹.
3. One clause of proof. A customer they know, or why you of all people understand the problem.
4. One ask, on its own line. About 15 minutes by phone or video, or a yes to something you’ll send.
5. Under 75 words. That’s Kolysh’s limit, and Abraham’s too. ^{6 5}

Casual is fine. Epstein takes “hey” more seriously than “Hello Mr. Epstein,” and says you can even have “no capitalization. Typos can be okay.” Both tell him a human wrote it ². A typo won’t hurt you; just never in their name, their company or a number. One caution: Lavender, an email-writing tool, finds in its own data that “neutral-slightly formal emails receive 11% more replies” ²⁵. So casual should mean plain words and contractions, not sloppy.

Read it out loud. Kolysh’s one-minute test: “Find a friend and just read your email out loud to them.” ⁶ Abraham’s: “If you wouldn’t say it to a friend, don’t say it in a cold email.” ²⁶ Cut anything you’d never say to a person: “I hope this finds you well,” your job title, a paragraph about your company, a feature list, “just circling back.”

Abraham’s test: “never send a cold email (for yourself or your client) that can be sent to another person and still make sense.” ²⁷ Generic praise fails it. Epstein’s example: “hey, love what you’re doing at Creative Market” reads like his company’s name dropped into a placeholder, while “I’m a huge Creative Market fan ever since you launched the photos category” shows the sender actually looked ².

The best findings are recent and tied to the problem: a job post, a funding round, a new leader, the tools they use, a gap you can see on their site, a complaint in their reviews (more on finding these in prospecting). Eric Nowoslawski, who runs the outbound agency Growth Engine X, warns that unrelated “attention hacks,” like where someone went to college, reveal “that you’re using automation, yielding nothing but eye rolls.” ²⁸ A shared past still works when it’s specific and rare: Epstein answered a stranger’s LinkedIn message that noticed they’d both had classes in the same campus building. ²

This is the part to hand to AI. Abraham: “AI has made deep segmentation practical at a scale that previously required too much manual research.” ²⁹ Let AI read each prospect’s site and posts and suggest how a finding connects to your offer. Then read the first batch yourself. Epstein’s warning still applies: language models “often struggle with a lot of this personal connection.” ² Write your first hundred or so by hand, and automate only what works.

These come from YC partners reading founders’ emails aloud and from Nick Abraham’s templates on X (he sells lead generation, so read his numbers as an agency’s). Lines in square brackets are paraphrased; templates keep their authors’ {{placeholders}}.

And one rewrite, from Abraham’s thread of before-and-afters ³³. The first version opens with the sender, a statistic and a 30-minute ask. The second opens with the reader, offers proof from a similar show and takes the risk away.

Once a first email gets some replies, split your next few hundred people into two to four groups of 100 to 200, and give each a different audience or offer. Test in this order:

1. Who: the job title and the kind of company. Gilbert: “Targeting beats perfect messaging.” ¹
2. The offer or angle. Abraham: “The angle and offer matter much more” than small wording changes ⁷.
3. The first line: which finding you lead with.
4. The ask: interest or a specific time (more below).
5. The subject line, judged by replies.

Why small tests lie. Send the same email to two groups of 300 at a 1% reply rate, and about half the time one will look at least twice as good by luck alone. Telling 1% from 2% reliably takes roughly 2,300 people per version (standard statistics, my arithmetic). So at founder scale, groups of 100 to 200 are for reading replies and spotting big differences, not crowning winners. At campaign scale, give each version a thousand or more; Abraham won’t even judge a sending domain on fewer than 1,000 emails and 48 hours ⁴.

Count the replies that matter. Open rates are noise now: Apple Mail opens emails automatically, so Smartlead doesn’t even report them ¹³. Abraham: “Reply rate is the only metric that matters. Everything else is vanity.” He also finds “77% of our replies are automated,” mostly out-of-office notes and people who’ve left ⁴. So count positive replies (interested people) and meetings booked per 100 emails. Gilbert’s yardstick: “two to three replies on 100 emails is a great place to start iterating.” ¹

If replies stay near zero, Gilbert checks in this order: the right person, the right companies, the subject line, only then the message, then your website and LinkedIn, and deliverability last. If all six look fine, she says the problem may be deeper: people may not want the product enough yet ¹.

One email isn’t enough. Epstein: “you should plan to manually follow up two, three, four times as needed,” with a few days between emails ². In Smartlead’s data, one email earned about 12 replies per 1,000 people and a three-email sequence about 25, so a single send leaves roughly half your replies on the table ¹³.

1. 1

   Day 1: the first email.

   Short, about them, one ask.

2. 2

   Day 4: add something useful.

   In the same thread: a resource, a quick finding, or the answer to the question they’re likely to have. Never just “checking in.”

3. 3

   Day 8: a new angle.

   Different proof, a fresh reason to talk now, or a smaller ask.

4. 4

   Day 13: the breakup.

   Assume a polite no and make it easy to say, like Gilbert’s breakup email in the examples ¹.

No one has a good study on same thread versus new thread; practitioners keep follow-ups in the same thread, and so would I. After the breakup, stop. Epstein: “Nobody owes you anything here. Just move on.” Check back in a couple of months if something changes ².

When they reply, answer fast. In Smartlead’s data, 64% of replies arrive within an hour ¹³. Gilbert wants founders to be “like a heat-seeking missile” once someone replies, because “time kills deals.” ¹ My rule: answer within the hour during your workday.

In every cold email, wherever you send it:

• Your real name and company.
• Your company’s postal address.
• A plain way to opt out, and a do-not-email list you check before every send.
• A note in your sheet of where you found each address.
• A subject line that matches the email. No fake “Re:” on a first email; the law bars deceptive subject lines ¹⁷.