leadarc.io
Cold Email Automation 101

Send 1,000+ cold emails a day without landing in spam.

This is the system we run every day, across every client account. It is built on one idea: volume comes from many small mailboxes, never from one big one. Here is the whole shape of it, so you can copy it.

What most people try
One mailbox. One thousand emails.
1,000
from a single mailbox

Google and Microsoft both watch how much a single mailbox sends. Push one mailbox this hard and it stops reaching inboxes within days. The domain goes with it.

What we do
Fifty mailboxes. Twenty emails each.
1 mailbox, 20 emails a day 1 domain holds 3 mailboxes
50 mailboxes × 20 emails = 1,000 a day

Every mailbox stays boring. Twenty emails a day looks like a person doing their job. Spread across 17 domains, no single domain carries enough traffic to get flagged. On Outlook the cap is 5 a day, so the same 1,000 needs 200 mailboxes.

The one law
Never trade deliverability for volume.

A system sending its full quota into the spam folder books zero meetings. When speed and safety pull against each other, safety wins every time. Every rule below exists to serve this one.

The whole thing on one page

How the parts fit together

Three stages. You build the sending fleet, you point it at the right people with the right words, then you turn what comes back into meetings. Everything below this map is the detail of one of these three boxes.

Sending platform 1 domain 3 mailboxes 17 domains · 50 mailboxes · 20 sends each = 1,000 a day Infrastructure Prospect database Score and verify Campaigns Google Microsoft Security gateways Everything else Targeting and copy Replies One shared inbox Sorted into 5 buckets and follow-up sequences Qualified meetings Paying clients Appointment setting
Infrastructure. One platform drives every domain. Each domain carries three mailboxes, and each mailbox sends twenty a day.
Targeting and copy. One list splits four ways by the recipient's mail provider. Same offer in all four, each running three to ten versions.
Appointment setting. Replies from every mailbox land in one place, get sorted, and get answered inside five minutes.
01

The sending infrastructure

Separate domains, many small mailboxes, and a reserve bench you never send from.

20 / 5Emails per mailbox per day
Never send cold email from your real company domain.
Buy separate sending domains that look like your brand. Point each one at your real site. If one gets burned, your real email keeps working.
Buy .com domains only.
Spam filters trust .com. Every other ending scores worse before you send a single email. When the .com is taken, add a word to it.
Put three mailboxes on each domain.
Fifty mailboxes needs about 17 domains. More than three per domain concentrates the risk.
SPF, DKIM and DMARC all pass before the first send.
These three DNS records prove the mail is really from you. Missing one sends you straight to spam. Start DMARC on monitor, then tighten it after a few clean weeks.
A Google mailbox sends 20 a day. An Outlook mailbox sends 5.
These caps are fixed. We never raise them to hit a number.
Need more volume? Buy more mailboxes.
Pushing an existing mailbox past its cap is the single fastest way to burn a domain.
A new mailbox warms for two to three weeks before it sends one cold email.
Then it climbs for four more weeks. Google opens at 10 a day and reaches 20 by week four. Outlook opens at 2 and reaches 5. Plan about six weeks from buying to full speed.
Every mailbox stays in warm-up forever.
Warm-up is quiet mail passed between your own mailboxes. It keeps the reputation alive. It never gets switched off, not even to free up sending room.
A quarter of your mailboxes never send.
They sit warm on the bench. When a domain burns, you swap a rested one in the same day and lose no volume.
Buy about 67 mailboxes to send from 50.
The reserve is part of the cost. Budget for it up front or you will be stuck the first time a domain goes down.
A replacement domain warms for two weeks before it swaps in.
You cannot buy your way out of a burned domain on the day. The bench only works if you built it early.
02

The list

A bad list burns good infrastructure. Who you email is a deliverability decision.

94% vs 60%Verified vs catch-all delivery
Score every company against your ICP before anyone gets an email.
Wrong-fit companies do not just fail to reply. They report you, and reports cost you the domain.
Verify every address, and load only the ones marked deliverable.
Verification costs a fraction of a cent per address. A burned domain costs weeks.
Throw away catch-all addresses.
About 60% of catch-alls actually land, against 94% for verified ones. Two campaigns we ran on catch-alls bounced at 13% and 18%, against about 5% on clean lists.
Keep a permanent list of every address that ever bounced.
Subtract it from every new list you build. The same dead address will come back to you from three different data sources.
Split your leads by the provider that hosts them.
Google, Microsoft, and heavily filtered domains each get their own campaign. One bad group then cannot drag down the others.
Refill a campaign before it runs dry.
We top up when a campaign has under 2.5 days of leads left. An idle campaign is a mailbox sitting at zero.
Recycle non-responders after 30 days.
The cheapest leads you own are the ones you already paid for. A new angle beats a new list more often than people expect.
03

The copy

Short, plain, and about them. Written so it reads like a person typed it.

500Sends before a winner counts
Send plain text. No HTML, no images, no logos, no colors.
Design in a cold email reads as marketing. Marketing reads as bulk. Bulk reads as spam.
Keep the email between 10 and 90 words.
Write it so a 12 year old could read it out loud without stumbling. Long and clever is the same as unread.
Subject lines are one to three plain words.
Lowercase, no punctuation, nothing that sounds like a headline. It should look like an email from a colleague.
Run several versions of the email at the same time.
Roughly one version per 100 emails of daily capacity. Four versions on a 400 a day campaign.
No winner until a version has 500 sends behind it.
1,000 to be confident. Anything less is noise dressed up as a result.
Judge on replies, never on opens.
We turn open tracking off, so opens do not exist for us. Replies are the only honest signal anyway.
Keep the winners, cut the losers, then write new versions off the winner.
Every round should start from the best thing you have already proved.
Proof beats adjectives.
“Cut missed calls from 40% to 5%” beats “we help businesses grow” every single time.
Every personalized field has a fallback word.
A missing first name should read “there”, never a blank or a raw token. One broken merge field tells the reader it is a blast.
Follow up in the same thread.
One opener plus one reply about two days later. A new thread for a follow-up reads as a second stranger.
04

The send

The settings decide as much as the words do. Most people lose here without knowing.

OffOpen tracking and unsubscribe
One launch becomes four campaigns.
Google, Microsoft, security gateways, and everything else. Only the gateway campaign uses the gateway mailboxes, so a blow-up costs you 15% of the fleet instead of all of it.
Turn open tracking off.
The tracking pixel is an invisible image, and an invisible image is a spam signal. The open numbers are wrong anyway.
No unsubscribe link in a cold email.
An unsubscribe footer tells the filter this is bulk mail. Answer every opt-out reply by hand instead, straight away.
Give every mailbox a real person's name and photo.
Forty mailboxes all named John Smith reads as a robot to Google. Vary the names the way a real company would.
Send inside business hours, in the prospect's timezone.
Mail arriving at 3am is a pattern no human makes.
Read a real test send on your phone before you launch.
Real lead data, real merge fields. The phone is the only honest preview of what they will see.
Check the sending days. Weekends are often on by default.
A cold email arriving on Saturday morning tells the reader a machine sent it.
All your campaign limits added up must fit your real capacity.
Otherwise the first campaign of the day drains the mailboxes and the rest sit at zero.
Pause a campaign before you edit it, then start it again.
Editing a campaign while it sends is how sequences break in the middle of a send.
Pace a campaign so it finishes when you want it to.
Cap the daily send at leads remaining divided by days left. Rushing a list is how you empty a campaign in three days and sit idle for ten.
05

The daily loop

One run a day, across every account, asking the same 13 questions in the same order.

13Questions, every account, daily

The funnel

  1. Are we sending?
  2. Are we landing in the inbox?
  3. Are we getting replies?
  4. Are we booking meetings?
  5. Can we do more?

The growth levers

  1. Can we refill the list?
  2. Can we send more per day?
  3. Can we add better copy?
  4. Can we buy more mailboxes?

Every single mailbox

  1. Is warm-up on?
  2. Is it sending cold email?
  3. Is it bouncing?
  4. Is it at full speed?
The check reports. A human decides. Then the machine acts.
Nothing touches a live campaign until a person says yes. Automated fixes are wrong often enough to cost you a domain.
A bounce rate over 2% is a warning. Over 3% is an emergency.
Measured once a campaign has passed 1,000 contacts. Below that the sample is too small to mean anything.
Read the bounce message before you blame the domain.
A 5.7.x code is a filter rejection, so your list is the problem. A 5.1.1 or 5.4.x is a dead address or a reputation problem. A 4.x is temporary and does not count.
One bad mailbox does not mean a bad domain.
Rest it for 48 hours first. Swap the domain only when it happens a second time.
Wait for 100 sends before you judge a mailbox.
One bounce out of nine looks like 11%. Small numbers lie loudly.
“Nothing is broken” is not the finish line.
The same run also hunts for the next ceiling: a campaign that could take more leads, more mailboxes, or a better angle.
06

The replies

Sending is the cost. Booked meetings are the only score that counts.

1 in 5,000Emails to meetings, healthy
Most replies are not leads.
Out of every ten replies, most are auto-responders and polite no's. Count interested replies, and ignore reply rate.
Every reply lands in one inbox.
Nobody is logging into 50 mailboxes. Replies that sit unseen for a day are meetings you already lost.
Answer inside 5 minutes.
Interest fades fast. The reply is warm for minutes, not hours.
Sort every reply into five buckets.
Book it, bad timing, wants information, wrong person, or a no. Each bucket gets its own next step.
“Not now” is not a no.
Tag it with the month they named and come back then. This is the cheapest pipeline you will ever build.
Chase the no-show.
A missed call is usually a calendar clash. One good re-book sequence recovers a large share of them.
Only buy more mailboxes once a campaign is booking.
Three meetings in the last month is our gate for spending money on more sending capacity. Scaling a campaign that books nothing just costs more.
The cheat sheet

Every number in one place

These are the thresholds we actually run on. Steal them as your starting point and adjust once you have your own data.

WhatNumberWhy that number
Google mailbox cap20 / dayFixed. Add mailboxes to grow, never raise this.
Outlook mailbox cap5 / dayMicrosoft is stricter than Google. Plan for four times the mailboxes.
Mailboxes per domain3Fifty mailboxes lands on about 17 domains.
Buy to full speedabout 6 weeksTwo to three weeks warming, then four weeks ramping.
Mailboxes owned per 50 sendingabout 67The 25% reserve is part of the cost, not an extra.
Warm-up ramp4 weeksGoogle climbs 10 to 13 to 16 to 20. Outlook climbs 2 to 3 to 4 to 5.
Active vs reserve75% / 25%A quarter of the fleet stays warm and idle, ready to swap in.
Bounce rate, warningover 2%Measured after 1,000 contacts. Time to look at the list.
Bounce rate, emergencyover 3%Stop and diagnose before it takes the domain.
Sample before judging a mailbox100 sendsUnder this, the percentage is meaningless.
Total reply rate floor0.9%Counting auto-replies. Below this you are in the spam folder.
Interested replies1 to 3 per 1,000Under 1 per 1,000 points at the offer rather than the infrastructure.
Meetings bookedabout 1 per 5,000Meetings are rare. Any booking is a real signal.
Winner declared at500 sendsPer version. 1,000 to be confident.
Versions per campaigncap / 100A 400 a day campaign runs about four versions at once.
Refill triggerunder 2.5 daysOf leads left at the current send rate.
Buy more mailboxes when3 meetingsIn the last month, on that campaign. This is the gate for spending.