How to Warm Up Email Domain Correctly: Proven Methods for 2025
You can write the perfect cold email — personalized, smart, and valuable.
But if it lands in spam, it doesn’t matter.
In 2025, deliverability isn’t about avoiding spam words. It’s about building trust with inboxes.
That trust comes down to two things:
- How people engage with your emails
- Whether they mark you as spam
If you're sending from a cold domain, getting no opens, or triggering spam complaints, filters notice.
And once your sender reputation drops, it’s tough to fix.
That’s why warming up your domain matters.
It’s not just a technical step — it’s what gets your emails seen.
In this guide, I’ll show you exactly how to warm up your domain the right way — whether you're starting from scratch or recovering from bad deliverability.
What Does It Mean to Warm Up an Email Domain?
Warming up an email domain means building trust with inbox providers (like Gmail, Outlook, Yahoo) by sending emails slowly and consistently over time, not all at once.
Think of it like building a credit score.
You don’t get approved for a big loan on day one. You prove you’re trustworthy with small actions over time.
It’s the same with email.
Why Do You Need to Warm Up a New Domain?
When you register a new domain, it has zero reputation.
Email providers don’t know if you’re legit… or just another spammer.
Things like:
- How many emails do you send per day
- How people engage with those emails (opens, replies, spam reports)
- If your emails look natural or automated
That’s why warming up is crucial.
You start by sending a small number of emails to real people who open, click, and reply.
Over time, inbox providers see that your domain is safe, and your deliverability improves.
Here’s what warming up helps with:
- ✅ Higher inbox placement (your emails avoid spam filters)
- ✅ Better open and reply rates
- ✅ A stronger sender reputation
- ✅ Less chance of being blacklisted
So, before launching that big cold email campaign or newsletter blast, make sure your domain is warmed up.
Or you’ll be shouting into the void.
How AI Has Changed Email Warm-Up in 2025
AI isn’t just writing emails anymore — it’s managing how those emails land in inboxes.
When it comes to domain warm-up, AI now takes care of the heavy lifting.
Warming up a domain used to be a hassle.
You had to:
- Send test emails to your own inbox
- Ask teammates to reply
- Manually track everything in a spreadsheet
It was slow, boring, and easy to mess up.
Now? AI handles all of that.
What’s Different in 2025 with AI
✅ Tools like Warmforge now handle warm-up automatically — no setup headaches
✅ They simulate real opens, replies, and even recover emails from spam folders
✅ The process mimics natural human behavior, so it passes provider filters
✅ Warm-up cycles finish in 7–14 days, not 4–6 weeks like before
✅ Your domain reputation improves faster, with fewer manual steps
This isn’t theory.
It’s how thousands of teams now warm up domains before launching cold outreach.
No more asking your team to open test emails.
No spreadsheets. No guesswork.
And if you’re still trying to do it manually in 2025, you’re not just behind — you’re putting your deliverability at risk from day one.
Why Should You Warm Up Your Email Domain?
If you skip warm-up and start blasting emails from a new domain, email providers will flag you — fast.
They don’t know who you are yet.
And if they see sudden activity with no history, it looks suspicious.
That’s how emails end up in spam.
Or worse, your domain gets blacklisted.
Warming up your email domain helps you avoid that.
Here’s why it matters:
1. You Avoid Spam Filters and Blacklists
New domains are watched closely.
Without a warm-up period, your emails can:
- Trigger spam filters
- Get marked as suspicious
- Be blocked entirely by some inbox providers
Once you’re blacklisted, it’s hard to recover.
Warm-up helps you stay under the radar — and stay clean.
2. You Get Better Inbox Placement
Email providers care about reputation.
A warm domain with steady activity is more likely to land in the inbox, not promotions or spam.
✅ Higher open rates
✅ More replies
✅ Fewer deliverability issues
3. You Build Long-Term Trust
Warm-up isn’t just a launch step. It sets the tone for your domain’s future.
When you start slow and steady:
- Your sender reputation grows
- Email tools learn to trust you
- Future campaigns perform better, even at scale
It’s like building a solid foundation.
If you do it right from the start, everything else becomes easier.
How Long Does It Take to Warm Up an Email Domain?
There’s no magic number — but on average, a proper email domain warm-up takes 4 to 6 weeks.
That gives inbox providers enough time to see your sending behavior, track engagement, and decide if you’re trustworthy.
But it’s not just about waiting.
What you do during those weeks matters.
Here’s what affects your warm-up speed:
1. Email Volume
Start small.
Most warm-up schedules begin with 10–20 emails per day and gradually scale up over time.
Sending too many too soon?
That’s a red flag — and a fast way to land in spam.
2. Engagement Metrics
It’s not just about how many emails you send — it’s about how people respond.
Inbox providers look at:
- Opens – If people aren’t opening your emails, their inboxes start ignoring you.
- Clicks – A click shows interest — even one tells providers your emails matter.
- Replies – Replies are the strongest signal that your emails are real and welcome.
- Spam Complaints – One spam click can ruin your warm-up; keep it at zero.
High engagement = faster trust.
If people ignore or report your emails, warm-up slows down.
3. Sending Frequency and Consistency
You can’t warm up a domain by sending once a week.
Consistency is key.
✅ Send emails every weekday
✅ Keep a regular schedule
✅ Avoid sudden spikes or long gaps
The more stable your activity, the more confident inbox providers feel.
Pro Tip:
With AI warm-up tools (like Warmforge), many teams now complete warm-up in 14–21 days, especially if the engagement looks natural and steady.
But if you're doing it manually, plan for the full 4–6 week window.
How to Warm Up Email Domain Step-by-Step (Proven Strategy)
Warming up your domain the right way means fewer bounces, better inbox placement, and higher reply rates.
Let’s walk through it — step by step.
Step 1: Set Up Domain Authentication
Before anything else, your domain needs to be verified and trustworthy.
You’ll need to set up 3 DNS records:
- SPF (Sender Policy Framework) — tells inboxes who’s allowed to send emails on your behalf
- DKIM (DomainKeys Identified Mail) — signs each email with a digital signature
- DMARC (Domain-based Message Authentication, Reporting & Conformance) — sets rules for how mail should be handled if it fails SPF or DKIM
How to do it:
- Log in to your domain host (GoDaddy, Namecheap, etc.)
- Find the DNS settings
- Add each record as TXT (your email provider will give you the values)
✅ Use tools like MXToolbox or Google Admin Toolbox to confirm they’re working.
No auth = no deliverability.
Step 2: Start With a Low Sending Volume
This is where most people mess up.
You can’t send 500 emails from a new domain on day one — it’ll trigger spam filters instantly.
Here’s a safe warm-up schedule:
💡 Send to real, verified inboxes (colleagues, seed lists, warm-up tools).
Step 3: Gradually Increase Volume and Frequency
Think of this like training.
You don’t skip straight to max reps.
Scale up slowly:
- Increase volume by 20–30% per week
- Spread emails out during the day
- Stick to weekday sends (avoid weekends)
🚫 Don’t jump from 50 to 500 emails overnight — inbox providers will notice.
Step 4: Focus on Engagement
Sending is just one part — what happens after matters more.
Inbox providers track:
- Opens – If people aren’t opening your emails, inbox providers think you’re irrelevant.
➤ Aim for 20–30 %+ to show Gmail and Outlook you’re a trusted sender. - Clicks – Clicks = interest.
➤ Even a few during warm-up tell inboxes that your emails offer real value. - Replies – Replies are your strongest trust signal.
➤ They show actual conversation — and boost domain reputation fast. - Spam Complaints – One “mark as spam” can undo everything.
➤ Keep your complaint rate near zero, or your warm-up could collapse.
How to boost engagement:
- Write personalized subject lines
- Avoid spammy language (no “Buy now” or “100% free”)
- Make it feel like a 1:1 conversation
📌 If no one’s opening your emails, pause. Adjust. Don’t scale noise.
Step 5: Stay Consistent With Sending Patterns
Sudden gaps or spikes? Not good.
Here’s how to keep things clean:
- Send emails daily, Monday to Friday
- Stick to normal business hours
- Don’t disappear mid-week or batch-send all at once
✅ A predictable schedule builds trust with inbox filters.
Step 6: Track Deliverability Metrics
Don’t guess. Monitor.
Use tools like:
- GlockApps - Monitor inbox placement across Gmail, Outlook, Yahoo, and more.
- Mail-Tester - Run a test email to check for spam triggers and missing records.
- MxToolbox - Quickly verify your SPF, DKIM, and DMARC DNS records.
Track:
- Open Rate: Aim for 30%+
- Bounce Rate: Keep it under 2%
- Spam Reports: Should be 0
⚠️ If numbers dip, stop scaling. Fix the problem first.
📝 Quick Recap
Here’s how to warm up your email domain step-by-step:
🔐 Set up SPF, DKIM, and DMARC
📉 Start with low volume (10–20/day)
📈 Increase slowly over 3–4 weeks
📬 Focus on engagement, not just sending
📆 Keep your schedule consistent
📊 Track performance with deliverability tools
Do this right, and your domain will stay clean — and your emails will actually reach people.
Warm-Up Timeline
Here’s a simple plan to follow if you’re warming up manually or even using a tool like Warmforge.
✅ Adjust volume based on engagement (opens, replies, complaint rate).
🚫 If bounce rates spike or opens drop, pause and reassess.
Stick to this warm-up plan, and by Week 4, your domain should be ready for real outreach — without the spam folder risk.
Common Mistakes to Avoid When Warming Up Email Domains
Warming up your domain isn’t just about sending emails — it’s about not screwing it up.
If you make one wrong move, your entire domain reputation could take a hit.
That means:
❌ Landing in spam
❌ Lost deliverability
❌ Weeks or even months wasted
Here are the biggest mistakes people still make in 2025 — and what they lead to:
If things dip, pause and fix it.
⚠️ One Bad Warm-Up Can Burn a Domain
If your warm-up fails, recovery is slow, or you may need a new domain.
Go slow, track everything, and don’t skip the basics.
Tools to Help You Warm Up Email Domain Automatically
Manually warming up a domain works — but it’s slow, inconsistent, and easy to mess up.
That’s why most teams now use AI-powered warm-up tools that handle everything for you in the background.
Here are some of the best tools to consider in 2025:
Quick Comparison: Best Email Warm-Up Tools in 2025
Let’s break them down in detail:
Warmforge
📌 Best for: Hands-off, reliable warm-up with deep deliverability tracking
Warmforge is purpose-built for cold outreach.
It creates real human-like activity (opens, replies, spam recovery) across a private, verified network, without manual effort.
Why people choose it:
- ✅ Runs 100% in the background
- ✅ Pulls emails out of spam
- ✅ Auto-adjusts volume daily
- ✅ Tracks inbox placement and bounce rates
💰 Pricing starts at $39/month — great value for teams that want speed and simplicity without risk.
🔗 Great for: Outreach teams, agencies, and founders who want to warm up fast — and safely.
Lemwarm (by Lemlist)
📌 Best for: Lemlist users who want everything in one place
If you're already sending emails with Lemlist, Lemwarm plugs right in.
It warms your domain inside the same dashboard — no third-party tools needed.
What it helps with:
- ✅ Gradual warm-up built into your campaign flow
- ✅ Real inbox interactions (opens, replies, threads)
- ✅ Reputation score monitoring
- ✅ Easy to turn on/off from Lemlist settings
💰 Add-on starts at $29/month on top of your Lemlist subscription — affordable and easy to manage from one place.
🔗 Great for: Founders, small teams, or anyone already using Lemlist.
TrulyInbox
📌 Best for: Agencies or teams managing multiple domains
TrulyInbox was built for volume.
If you’re running outreach for multiple clients or inboxes, it keeps everything organized.
Why agencies love it:
- ✅ Multi-inbox support from one dashboard
- ✅ Daily warm-up activity and placement reports
- ✅ AI-based human-like behavior simulation
- ✅ Alerts when your domain is safe to scale
💰 Plans start at $35/month, with higher tiers for more inboxes — flexible for solo users and large teams alike.
🔗 Great for: Consultants, lead-gen firms, or multi-inbox teams.
How to Know When Your Email Domain Is Warmed Up?
Just because you’ve been warming up for a few weeks doesn’t mean your domain is ready.
You’ll need to check a few key signals — the kind of inbox providers look for before they start trusting you.
Here’s how to know when it’s safe to start real outreach:
Your Deliverability Is High and Consistent
If your emails are consistently landing in the inbox, not promotions or spam — that’s your first green flag.
You’re looking for:
- 90 %+ delivery rate
- No hard bounces or rejections
- No random blocks from Gmail, Outlook, or Yahoo
Use tools like GlockApps or your warm-up dashboard to check inbox placement.
Your Open Rates Are Holding Steady
Warmed-up domains have solid open rates that don’t fluctuate wildly.
You want to see:
- Open rates are sitting at 20–30% or more
- Stability as you slowly increase volume
- No sudden drops (which could mean a reputation issue)
Platforms like Lemlist, Instantly, and Mailshake help you monitor open trends.
Your Bounce Rate Is Low
High bounce rates are a sign your email list is bad, or your domain isn’t trusted yet.
Your target:
- Bounce rate under 3%, ideally closer to 1%
- No spikes as you ramp up daily volume
- Mostly verified, active recipients
Tools like Mail-Tester, SendGrid, or your email provider’s analytics help you track this.
Spam Complaints Are Basically Zero
Spam reports kill your domain faster than anything.
If even a few people mark your email as spam during warm-up, you’ll lose trust fast.
✅ What do you want?
- Complaint rate close to 0.0%
- No feedback loop alerts
- No warnings from your email platform
Check your ESP’s reporting or use Gmail Postmaster Tools if available.
You’re Passing Deliverability Tests
Before scaling, run a quick test using online tools.
You’re looking for:
- ✅ Valid SPF, DKIM, and DMARC
- ✅ No major spam triggers
- ✅ Inbox placement across major providers
Use tools like Mail-Tester, MXToolbox, or EasyDMARC for peace of mind.
📝 Quick Recap: Signs You’re Ready
Your domain is likely warmed up when:
- ✅ 90%+ deliverability
- ✅ Open rates stay above 20–30%
- ✅ Bounce rate is under 3%
- ✅ No spam complaints
- ✅ Inbox placement tests come back clean
If all that checks out for 3–5 days straight, you’re good to go.
Conclusion: Warm-Up Isn’t Optional. It’s the Foundation.
Most cold email campaigns fail before they even start.
Why? Because the sender skips domain warm-up, or does it wrong.
And once inbox providers lose trust in your domain, it’s almost impossible to get it back.
You’ll be stuck in spam, wasting good leads and time.
Warming up your email domain the right way gives you:
- ✅ Higher inbox placement
- ✅ Stronger sender reputation
- ✅ Better results from every single campaign
You can do it manually — slowly, carefully, day by day.
But if you want to scale fast and reduce risk, use the right tool from the start.
Tools like Warmforge don’t just make domain warm-up easier.
They make it automatic.
It mimics real email activity, handles daily sending, pulls you out of spam, and tracks everything that matters.
So you can focus on writing better emails, not fixing deliverability problems.
If you’re serious about results, don’t skip warm-up.
👉 Try Warmforge free trial and start landing in more inboxes from day one.
FAQs
- How long does it take to warm up a domain?
Warming up a domain usually takes 2 to 4 weeks, based on how often you send and how people respond.
If you use a tool like Warmforge, it’s faster - about 10 to 14 days - since it simulates real engagement every day.
- Can I skip warm-up if I’m sending a small number of emails?
Even if you're sending just 50 emails a day, skipping warm-up is risky.
Providers look for gradual sending patterns and engagement history. A cold domain with sudden activity — even at low volume — can still trigger spam filters.
- What happens if I don’t warm up my domain?
Your emails might:
- Go straight to spam
- Bounce more often
- Get your domain flagged or blacklisted
This not only kills your campaigns - it can affect all future emails sent from that domain.
- Do I need to warm up a domain if I already warmed up an inbox?
Yes. Warm-up happens at the domain level, not just the inbox.
Even if an inbox is aged or active, if the domain is new or hasn’t sent outbound emails before, it still needs warming up.
- Can I use multiple tools to warm up faster?
No — that’s actually dangerous.
Using multiple tools can confuse inbox providers, spike volume unnaturally, and hurt your domain reputation. Stick to one trusted warm-up tool with solid engagement simulation.
- What’s the best tool to warm up my email domain in 2025?
Warmforge is a top choice for 2025.
It automates daily sending, simulates real replies, pulls emails out of spam, and shows you exactly when your domain is ready — no manual work required.