Email Warm-Up Engine
Why the emails land in the inbox, not spam.
Your AI SDR sends cold email around the clock. Without a warm inbox, those emails hit spam before a prospect ever reads them. FirstSales runs a 21-day warm-up automatically, and it is why 87% of sends land in the primary inbox instead of the 60-70% industry average.
- Automated 21-day ramp builds sender reputation before your first send
- Private headless-browser network: 50,000+ real accounts
- Live deliverability dashboard so you know exactly when to hit send
$1 for 3 days · Cancel anytime · Warm-up included in every plan
87%
Avg inbox rate
21
Day ramp
50k+
Warmup accounts
Free
Included in all plans
The Network
The biggest deliverability network in cold email
A bigger pool means faster reputation growth. 50,000+ real accounts, 2M+ daily warmup emails, and a private headless-browser network that keeps your domain safe.
50,000+ Active Email Accounts
Most warmup tools have 5,000-10,000 accounts, which limits how fast your reputation grows.
FirstSales runs 50,000+ real email accounts in its warmup pool, the largest available.
2M+ Daily Warmup Emails
Low daily volume means slow reputation growth and delayed results for your campaigns.
Our network sends 2M+ warmup emails every day, building your reputation faster than any competitor.
99.7% Uptime
Network downtime breaks warmup continuity and hurts your sender reputation progress.
Redundant infrastructure keeps warmup running 24/7 so your reputation never stalls.
87% Average Inbox Rate
The industry average for basic warmup is 60-70%, leaving 30-40% of emails in spam.
FirstSales averages 87% inbox placement after the 21-day ramp, every plan included.
Zero Spam Complaints
Poorly managed warmup networks can trigger spam complaints that blacklist your domain.
Our private, isolated network has zero spam complaints. Your domain stays clean.
24/7 Automated Monitoring
Manual monitoring means missed issues and slow responses when placement dips.
Real-time monitoring catches inbox placement drops within hours, not weeks.
Industry average inbox placement:
60-70%
FirstSales:
87%
How It Works
One click to start. 21 days to land in every inbox.
Once your email accounts are connected to FirstSales, activating warm-up is a single toggle. From there, the engine handles everything automatically.
8 min
Setup
21 days
Ramp duration
87%
Avg inbox rate
Unlimited
Accounts
Connect your email accounts
Add Gmail, Outlook, or any major provider in seconds. OAuth-secured, one-click connection, unlimited accounts.
- One-click OAuth
- All major providers
- Unlimited accounts
Enable warm-up in one click
Flip the switch and our private network starts interacting with your emails automatically. No manual work, no configuration required.
- Instant activation
- AI-generated conversations
- Human-like behavior
Watch your reputation grow
Your deliverability score climbs day by day. The live dashboard shows exactly where you are and when you are ready to send.
- Real-time dashboard
- Daily progress report
- Ready-to-send signal
Setup in 8 minutes. $1 for 3 days.
Deliverability Dashboard
Know exactly where every email lands
Your deliverability score updates in real time. See inbox placement, spam rate, open rate, and reply rate for every account so you know when you are ready to send.
94%
Inbox Placement
4%
Spam Folder
67%
Open Rate
23%
Reply Rate
Warm-up progress
Health score
Real-time insights included with every account
Smart Warmup
The slow ramp: 2 emails on day 1, 50+ by day 21
Jumping straight to high volume is how domains get blacklisted. The slow ramp starts low, climbs steadily, and signals to every inbox provider that your sender is a real human, not a spam operation.
2
Day 1
15
Day 7
30
Day 14
50+
Day 21
Week 1 warmup schedule
Gradual IncreaseDay 1
2
emails
Day 2
4
emails
Day 3
6
emails
Day 4
8
emails
Day 5
10
emails
Day 6
12
emails
Day 7
15
emails
Protect your domain
Gradual volume increase prevents spam filters from flagging your account as suspicious during the critical early sends.
Organic growth pattern
The ramp mimics natural human behavior that email providers expect from legitimate senders, not mass-blast tools.
21-day optimal timeline
Research-backed duration to establish maximum sender reputation and trust before your AI SDR fires its first campaign.
Automatic volume adjustment included in every plan
Private Network
A private network of headless browsers, not basic email servers
Basic warmup tools send bot emails from shared servers. Spam filters flag those within days. FirstSales uses a private headless-browser network that looks and behaves like real humans, because it does.
Headless Browser Network
Most warmup tools use basic email servers that can be detected and blocked by providers.
Our private network of headless browsers guarantees safe, effective, undetectable warmup.
100% Private and Secure
Some tools expose your data to third parties or mix warmup emails with real prospect data.
All warmup emails stay inside our private network. Your data never leaves our ecosystem.
Global IP Distribution
Single-region activity looks suspicious and triggers spam filters for bulk senders.
Warmup traffic comes from diverse IPs across multiple regions, mimicking real-world patterns.
Scalable Infrastructure
Small networks degrade performance as the user base grows, hurting everyone.
Our network scales automatically so quality stays consistent regardless of volume.
Human-Like Interactions
Robotic clicking patterns are easily detected and flagged by spam filters within days.
Emails are opened, scrolled, and replied to exactly as a real person would behave.
Verified Accounts Only
Low-quality accounts in a warmup pool can drag down your sender reputation fast.
Every account in our 50,000+ pool is verified and monitored for maximum deliverability.
Advanced Controls
Defaults work great. Power users go further.
Our default warmup settings are tuned to deliver 87% inbox placement out of the box. If you want to fine-tune every variable, the controls are there.
Read Emulation
Basic warmup just opens emails without reading, which looks robotic and suspicious.
Our system scrolls through warmup emails at human reading speed, building authentic engagement signals.
Random Volume
Predictable daily send counts are a known signal that spam filters flag immediately.
Send a random number of warmup emails each day so your pattern looks organic.
Custom Open Rate
Fixed open rates don't match your domain's natural engagement patterns over time.
Choose the exact open rate you want for warmup emails to match your sender profile.
Reply Rate Control
Without replies, your warmup lacks the two-way engagement credibility needs.
Set your desired reply rate for warmup conversations to build authentic conversation signals.
Spam Protection Level
Aggressive settings can trigger spam filters and erode the domain reputation you built.
Adjust protection levels to match your current domain reputation and sending history.
Custom Schedule
Sending at wrong times looks unnatural for your timezone and target market.
Define exactly when warmup emails go out to match your real sending window.
Warmup Settings
All advanced settings included in every plan
Proof
Founders and SDRs hitting 87% inbox placement
21-day
Warm-up
<2%
Bounce rate
87%
Avg inbox placement
“First sales is a wonderful service we purchased for our companies growth and the tools are preparing us to take things to the next level. It's an ALL IN ONE insane solution!!”
Raoul J.
Small-Business (50 or fewer emp.)
“The outreach and prospector feature is a complete package any salesperson would need. It helps me prospect and reach from a single location.”
Dishant S.
Partner, Small-Business
“Firstsales.io offers a comprehensive solution for cold emailing and outreach, with a user-friendly interface and enterprise-level capabilities.”
Aditya S.
Small-Business (50 or fewer emp.)
“I really appreciate that they have made the onboarding process much simpler than other cold emailing platforms I have used.”
Michael O.
Developer, Small-Business
“One of the best email outreach tools I have ever seen in my 9 years of business experience. Everything runs so cool and flawless.”
Santhosh H J
Business Owner
“It can automate email follow-ups for warm leads. The AB testing feature is pretty amazing, better than lots of other tools.”
Tim C.
Founder, Small-Business
$1 for 3 days. Cancel anytime.
Your AI SDR needs a warm inbox. Start the 21-day ramp today.
Join founders and SDRs reaching 87% inbox placement. Warm-up, list cleaning, and live monitoring are included in every plan from $29/mo. Competitors charge $94-358/mo and still skip the deliverability engine.
General
Deliverability
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