12 Best Email Warmup Tools + Pricing

An email warmup service is a platform that builds trust for your email accounts by simulating real conversations with other inboxes. These tools send, open, reply to, and mark emails as important across a network of real addresses, gradually increasing your sender reputation with email service providers (ESPs).

Without warmup, cold emails sent from new or low-activity domains are almost certain to land in spam folders. The warmup process typically takes 3 to 4 weeks of consistent automated activity before your domain earns enough trust to reliably reach primary inboxes.

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Key Terms

Email Warmup: The process of gradually increasing sending volume and engagement on a new or low-activity email account to build a positive sender reputation with email service providers like Gmail, Outlook, and Yahoo.

Sender Reputation: A score that ESPs assign to your domain and IP address based on your sending history, engagement rates, bounce rates, and spam complaints. Higher reputation means better inbox placement.

Inbox Placement Rate: The percentage of your emails that land in the recipient’s primary inbox rather than spam, junk, or promotions folders. This is the key metric for measuring warmup effectiveness.

ESP (Email Service Provider): The service that receives and filters incoming email for recipients. Gmail, Outlook, Yahoo, and Zoho are common ESPs that evaluate your sender reputation before deciding where to place your messages.

DNS Authentication: Technical records (SPF, DKIM, DMARC) configured on your domain that verify you’re an authorized sender. Proper DNS setup is a prerequisite for successful email warmup.

Warmup Network: The pool of real email accounts that a warmup tool uses to exchange messages with your domain. Larger networks with diverse ESPs typically produce stronger reputation signals.

Inbox Rotation: The practice of distributing your sending volume across multiple email accounts to avoid triggering spam filters on any single account. Many warmup platforms include this feature.

Why Email Warmup Matters

If you’re running a cold email strategy, email warmup is a practical necessity. Starting a campaign from an address without a strong reputation sends most of your messages straight to spam.

The Benefits of Email Warmup

Inbox placement instead of spam: Warmup tools train ESPs to trust your domain by generating authentic-looking engagement. Brands that warm up their accounts see significantly better inbox placement, allowing them to avoid going to spam and reach their intended audience.

Higher open and response rates: Emails that reach the primary inbox get read. When your messages clear spam filters consistently, your open rates and response rates both climb because recipients actually see your messages.

Stronger ESP reputation: Building trust with one ESP often improves your standing across others. A solid warmup strategy creates a positive reputation that carries across Gmail, Outlook, Yahoo, and other providers.

Scalable outreach: Once your domain is warmed, you can gradually increase your daily sending volume without triggering spam filters. This foundation makes it possible to scale campaigns from dozens to thousands of emails per day.

Key Insight

In our testing, the warmup phase is the single most overlooked step in cold email campaigns. Teams that skip warmup and jump straight to sending typically see 20-40% of their emails land in spam. After 3 to 4 weeks of proper warmup, that number drops below 5% for most domains.

The 12 Best Email Warmup Tools

1. Smartlead.ai

Quick Summary

Smartlead is a cold email platform with unlimited email accounts and built-in AI-powered warmup on every plan. It uses OpenAI integration to generate natural-sounding warmup emails instead of nonsensical placeholder text.

Smartlead includes unlimited warmup as part of its cold email infrastructure. The platform uses dynamic IP addresses, auto-mailbox rotation, and AI-generated warmup content that mimics real conversations. Over 31,000 businesses use it to scale outbound campaigns.

The centralized master inbox lets you manage replies across all connected accounts in one place. Smartlead also offers automated sequences, detailed analytics for opens and replies, and email verification. It’s particularly popular with lead generation agencies managing multiple client campaigns.

Pricing: Basic at $39/month ($32.50/month annual) for 2,000 leads and 6,000 emails. Pro at $94/month for 30,000 leads. Custom from $174/month. All plans include unlimited email accounts and warmup.

Key Features:

• Unlimited email accounts and warmup on every plan
• AI-generated warmup emails using OpenAI integration
• Dynamic IP addresses and auto-mailbox rotation
• Centralized master inbox for managing all conversations
• 14-day free trial with full feature access

Who Should Choose Smartlead

• Lead generation agencies managing multiple client inboxes under one account
• Teams warming up 5+ email accounts who want unlimited warmup at a flat rate
• Cold email senders who want warmup bundled with campaign management

2. Warmy.io

Quick Summary

Warmy.io is an AI-driven email warmup platform that uses its proprietary “Adeline” engine to automatically adjust sending volume based on your domain’s health. It supports 30+ languages and is compatible with Gmail, Outlook, Microsoft 365, Yahoo, Zoho, and SMTP.

Warmy.io stands out for its template warmup feature, which lets you test your actual sales email copy to see if it triggers spam filters before you launch a campaign. The platform also monitors domain health in real time and offers free tools including an Email Deliverability Test, SPF Record Generator, and DMARC Record Generator.

The multi-language warmup support is valuable for teams running outreach in non-English markets. Over 7,000 businesses use Warmy.io, and the platform offers 24/7 customer support with a 7-day free trial on all plans.

Pricing: Starter at $49/month (100 daily warmup emails). Business, Scale, and Premium plans available at higher tiers. Platinum at $429/month (5,000 daily warmup emails). Two months free on annual billing.

Key Features:

• AI “Adeline” engine that auto-adjusts warmup volume based on domain health
• Template warmup to test your actual email copy against spam filters
• Multi-language warmup support in 30+ languages
• Free deliverability test, SPF/DMARC generators, and email health checker
• 7-day free trial with access to all premium features

Who Should Choose Warmy.io

• Teams running outreach campaigns in non-English languages
• Senders who want to test their actual email templates for spam triggers before launching
• Businesses that need deep domain health monitoring alongside warmup

3. TrulyInbox

Quick Summary

TrulyInbox is an AI-powered email warmup tool that helps users build a strong sender reputation. It sends emails like a human one at a time, at different intervals, to make interactions look real and natural.

The platform works with all major email providers, including Gmail, Outlook, Microsoft 365, Zoho, and Yahoo. Users can connect unlimited email accounts and manage them all from one dashboard. TrulyInbox also shows a deliverability score so users can track their inbox placement and catch problems early.

TrulyInbox’s AI-powered approach differentiates it from simpler warmup tools. Rather than blasting out generic messages, the system varies send times, content, and engagement patterns to mimic authentic human behavior. This makes the warmup activity virtually indistinguishable from real email usage, which produces stronger reputation signals with ESPs.

Pricing: Free plan with 1 email account and 10 warmup emails per day. Paid plans start at $22/month (billed annually) with unlimited email accounts. 7-day free trial on all paid plans with no credit card required.

Key Features:

• AI-powered warmup that mimics human sending patterns
• Compatible with Gmail, Outlook, Microsoft 365, Zoho, and Yahoo
• Unlimited email accounts on paid plans
• Deliverability score tracking to monitor inbox placement
• Free plan available plus 7-day trial with no credit card required

Who Should Choose TrulyInbox

• Teams that want AI-driven warmup with natural human-like sending patterns
• Budget-conscious senders who want a free plan to start
• Businesses warming up multiple accounts who need unlimited inbox support at low cost

4. Warm Up Your Email

Quick Summary

Warm Up Your Email is the only tool on this list that uses human-written emails instead of auto-generated content. A team of real people writes and replies to your warmup messages, creating the most authentic engagement signals possible.

The service sends automated emails from your accounts to its network of inboxes, then has human emailers reply manually. If your emails land in spam, the team removes them from spam folders, which helps repair a damaged ESP reputation over time.

You also get analytics showing how many of your emails land in spam versus inbox for each ESP. The service is provided free to Mailshake users, making the two tools a natural pairing for teams already using Mailshake for cold email outreach.

Pricing: $29/month per inbox. Free for Mailshake users.

Key Features:

• Human-written warmup emails instead of AI-generated or nonsensical content
• Manual replies from real people to maximize engagement authenticity
• Spam folder rescue to repair damaged sender reputations
• ESP-specific analytics showing inbox versus spam placement
• Free for Mailshake subscribers

Who Should Choose Warm Up Your Email

• Senders who want the most authentic warmup engagement from real human writers
• Teams with damaged sender reputations that need spam folder rescue
• Mailshake users who get the service included at no extra cost

5. Mailflow.io Auto Warmer

Quick Summary

Mailflow.io Auto Warmer (originally from QuickMail) is a free email warmup tool compatible with Gmail and Outlook. It requires approval to join the warmup network, which adds a layer of quality control that many paid alternatives lack.

After Gmail restricted auto warmup services, QuickMail moved this tool to Mailflow.io. You’ll need to start a free trial (which requires a credit card) to access the Auto Warmer, but the warmup feature itself remains free even after the trial expires.

The approval-based network membership means you’re exchanging warmup emails with vetted accounts rather than random or low-quality inboxes. For teams on a tight budget, this is the strongest free option available.

Pricing: Free (credit card required for initial trial signup).

Key Features:

• Completely free email warmup for Gmail and Outlook
• Approval-based network membership for higher-quality engagement
• Clean, simple interface with automated setup
• Continues working after the free trial period ends
• Backed by QuickMail’s cold email infrastructure

Who Should Choose Mailflow.io Auto Warmer

• Budget-conscious teams that need free warmup without compromising quality
• Solo senders warming up 1 to 2 accounts who don’t need advanced analytics
• QuickMail users who want a seamless warmup integration

6. SalesHandy

Quick Summary

SalesHandy is a cold email automation platform with built-in email warmup for unlimited inboxes on every plan. It sends warmup emails to legitimate addresses that read, reply to, and mark your messages as important.

SalesHandy’s warmup tool lets you warm up multiple email domains simultaneously while tracking progress through daily reports, a predicted deliverability percentage, and an email health score. The platform also monitors your email and domain age to flag potential reputation risks.

Beyond warmup, SalesHandy offers a full cold outreach suite with unlimited email account connections, inbox rotation, A/B testing, and a native B2B lead database. Over 100,000 users rely on the platform, including teams at companies like Uber, Oracle, and Microsoft.

Pricing: Outreach Starter at $25/month (annual). Outreach Pro at $74/month. Scale at $149/month. All plans include unlimited email accounts and warmup.

Key Features:

• Unlimited inbox warmup on every plan
• Daily reports with deliverability predictions and email health scores
• Email and domain age monitoring
• Full cold outreach suite with sequences, A/B testing, and inbox rotation
• Native B2B lead database with verified contacts

Who Should Choose SalesHandy

• Cold outreach teams that want warmup bundled with a full campaign platform
• Agencies warming up many accounts who need unlimited inbox support
• Businesses that also need a built-in lead database for prospecting

7. WarmUp Inbox

Quick Summary

WarmUp Inbox uses AI writers to generate dynamic warmup content across a network of over 30,000 real B2B inboxes. It supports topic-specific and language-specific warmup for more targeted reputation building.

WarmUp Inbox is a set-it-and-forget-it service that’s compatible with Gmail and Outlook. The platform’s standout feature is its topic and language customization, which lets you warm up your inbox with content relevant to your industry rather than generic placeholder text.

The network of real B2B email accounts (rather than bot-created addresses) produces higher-quality engagement signals. Plans are straightforward with no hidden fees.

Pricing: Basic at $15/month per inbox (50 daily warmup emails). Pro and Max plans available at higher tiers.

Key Features:

• AI-generated dynamic warmup content across 30,000+ B2B inboxes
• Topic-specific and language-specific warmup customization
• Compatible with Gmail and Outlook
• Simple setup with automated daily management
• Real B2B inboxes rather than bot accounts

Who Should Choose WarmUp Inbox

• Senders who want topic-specific warmup content matched to their industry
• Teams warming up 1 to 3 inboxes who want affordable per-inbox pricing
• Non-English senders who need language-specific warmup options

8. Lemwarm

Quick Summary

Lemwarm was the original email warmup service that spawned the entire category. Built by the Lemlist team, it connects your inbox to a peer-to-peer network of other Lemwarm users and automatically generates warmup emails with entertainingly bizarre subject lines.

Lemwarm’s adaptive system increases your warmup volume based on your sending history, making the growth look natural to Gmail, Outlook, and other providers. It also lets you choose a warmup topic relevant to your industry, so your warmup emails go to accounts that match your niche rather than random inboxes.

The platform includes sender reputation monitoring with alerts if your deliverability score drops. You can warm up your own email templates to see how they perform before launching a campaign. Lemwarm is now bundled into Lemlist’s paid plans.

Pricing: Essential at $24/month per inbox (annual). Smart at $40/month per inbox (annual). Also included in Lemlist Email Pro ($79/user/month) and Multichannel Expert ($109/user/month) plans.

Key Features:

• Industry-specific warmup network that matches your niche
• Adaptive volume increase based on your sending history
• Sender reputation monitoring with automated alerts
• Template warmup to test your actual outreach emails
• Bundled into Lemlist plans for users who also need cold email sequences

Who Should Choose Lemwarm

• Lemlist users who want warmup integrated directly into their outreach platform
• Senders who want industry-specific warmup matching rather than generic exchanges
• Teams that need sender reputation monitoring alongside warmup

9. Folderly

Quick Summary

Folderly is a comprehensive email deliverability platform that goes beyond basic warmup. It uses AI to create genuine-looking conversations, diagnoses why emails land in spam, verifies DNS authentication, and analyzes email content for spam triggers.

Folderly’s warmup uses GPT-powered interactions to generate templates for any industry. The platform also provides automated senders for mailbox security and progress tracking so you know exactly when your domain is ready for bulk campaigns.

What sets Folderly apart is its diagnostic approach. Instead of just warming your inbox, it identifies specific reasons your emails might be hitting spam, including content issues, DNS misconfigurations, and blacklist problems. This makes it valuable for repairing damaged reputations, not just building new ones.

Pricing: Warmup plans start at $49/month per inbox. Full deliverability suite at $96/month per inbox. Custom enterprise pricing available.

Key Features:

• AI-powered warmup with GPT-generated industry-specific content
• Spam diagnosis that identifies specific deliverability problems
• DNS record verification and authentication monitoring
• Email content analysis with improvement suggestions
• Integrates with Gmail, Outlook, and most major ESPs

Who Should Choose Folderly

• Businesses with damaged sender reputations that need diagnosis and repair
• Enterprise teams that want a full deliverability ecosystem beyond basic warmup
• Senders who need to understand why their emails land in spam, not just fix the symptom

10. Mailwarm

Quick Summary

Mailwarm is a premium warmup tool that focuses on high-quality engagement signals. Your emails are opened, moved out of spam, marked as important, and replied to by inboxes in its network of 1,000+ accounts.

Mailwarm offers a customizable warmup schedule, letting you control the daily volume and cadence of warmup emails. The platform also provides analytics and reporting on your warmup progress. Setup takes about 2 minutes.

The main drawback is price. At $69/month for a single inbox with 50 daily warmup emails, Mailwarm is the most expensive per-inbox option on this list. The network is also smaller than competitors like WarmUp Inbox (30,000+) or Warmbox (35,000+). For teams warming up multiple accounts, unlimited-plan alternatives offer far better value.

Pricing: Starter at $69/month per inbox (50 daily emails). Growth at $159/month (200 daily emails). Scale at $479/month (500 daily emails). Two months free on annual billing.

Key Features:

• Spam folder rescue with opens, replies, and “mark as important” actions
• Customizable warmup volume and schedule
• Analytics and reporting on warmup progress
• 2-minute setup with automated daily management
• Compatible with Gmail, Outlook, and SMTP

Who Should Choose Mailwarm

• Senders warming up a single high-value inbox who prioritize engagement quality
• Teams with generous budgets who want a simple, premium warmup experience
• Users who don’t need the additional cold email tools bundled by competitors

11. Warmbox

Quick Summary

Warmbox uses GPT-4-powered AI to generate realistic warmup emails across a network of 35,000+ inboxes in 100+ countries. It offers granular control over warmup scenarios with three pre-built recipes and a custom configuration option.

Warmbox automatically removes emails from spam, marks messages as important, and creates natural engagement patterns. The platform includes a domain blacklist checker and DNS deliverability checker for monitoring your reputation alongside the warmup process.

The customization options are stronger than most competitors. You can adjust email timing, volume, reply rates, and choose from pre-suggested warmup scenarios or build your own. Daily reports track your warmup activity and provide a deliverability score on a 0-to-100 scale.

Pricing: Solo at $19/month (1 inbox, 50 daily emails). Start-Up at $59/month (3 inboxes). Growth at $99/month (6 inboxes). No free trial currently available.

Key Features:

• GPT-4-generated warmup emails across 35,000+ inboxes in 100+ countries
• Three pre-built warmup recipes plus custom scenario builder
• Domain blacklist checker and DNS deliverability checker
• Daily reports with a 0-to-100 deliverability score
• Compatible with all major ESPs via SMTP

Who Should Choose Warmbox

• Tech-savvy marketers who want granular control over their warmup configuration
• Teams warming up 1 to 6 inboxes who want detailed scenario customization
• Senders who need integrated blacklist and DNS monitoring

12. InboxWarm

Quick Summary

InboxWarm, offered by OutreachBin, is an email warmup tool that operates on a peer-to-peer network. Your domain exchanges warmup emails with real businesses that are also warming their accounts, creating authentic two-way engagement.

InboxWarm’s peer-to-peer model means you’re not exchanging emails with bot accounts or fabricated inboxes. The warmup interactions happen between real businesses actively using the service, which generates stronger engagement signals for ESPs.

The tool also gives you access to OutreachBin’s broader cold email service suite, including campaign management and analytics. Setup is straightforward, though no free trial is currently available.

Pricing: Starting at $29/month per inbox (40 warmup emails per day). No free trial.

Key Features:

• Peer-to-peer warmup network with real business accounts
• Automatic human-like interaction (opens, replies, engagement)
• Visual analytics on warmup email performance
• Access to OutreachBin’s cold email service suite
• Straightforward setup and automated daily management

Who Should Choose InboxWarm

• Senders who want peer-to-peer warmup with real business accounts rather than bots
• OutreachBin users who want warmup integrated with their existing outreach tools
• Teams that value authentic engagement signals from business-to-business exchanges

Pro Tip

Start your warmup at least 3 weeks before your first cold email campaign. We’ve found that rushing the warmup period or sending campaign emails too soon undermines the entire process. Patience during warmup translates directly to better inbox placement once you go live.

Comparison Table

#	Tool	Starting Price	Pricing Model	Free Plan/Trial	Best For
1	Smartlead.ai	$39/mo	Flat fee (unlimited inboxes)	14-day free trial	Agencies scaling many inboxes
2	Warmy.io	$49/mo	Per inbox	7-day free trial	Multi-language warmup + diagnostics
3	TrulyInbox	$22/mo	Per inbox (free plan available)	Free plan + 7-day trial	AI-powered warmup with unlimited accounts
4	Warm Up Your Email	$29/mo	Per inbox	Free for Mailshake users	Human-written warmup emails
5	Mailflow.io	Free	Free	Yes (free forever)	Budget-conscious senders
6	SalesHandy	$25/mo	Flat fee (unlimited inboxes)	7-day free trial	Warmup + cold outreach + lead data
7	WarmUp Inbox	$15/mo	Per inbox	No	Topic-specific warmup on a budget
8	Lemwarm	$24/mo	Per inbox	Free trial available	Industry-matched peer network
9	Folderly	$49/mo	Per inbox	No	Deliverability diagnosis + repair
10	Mailwarm	$69/mo	Per inbox	No	Premium single-inbox warmup
11	Warmbox	$19/mo	Per inbox	No	Customizable warmup scenarios
12	InboxWarm	$29/mo	Per inbox	No	Peer-to-peer business network

Evaluating These Tools

We evaluated each tool based on warmup network size, AI content quality, deliverability monitoring features, pricing model, and user reviews on G2 and Capterra. Tools with unlimited inbox pricing scored higher for teams warming multiple accounts, while per-inbox tools were judged on the depth of their individual features.

The most significant pricing distinction is flat-fee versus per-inbox billing. If you’re warming up more than 2 to 3 accounts, platforms like Smartlead and SalesHandy offer dramatically better value than per-inbox tools charging $29 to $69 per account.

Measuring Your Warmup Results

Most warmup tools report inbox placement rates, spam folder rates, and engagement metrics for warmup emails. But these numbers only tell you whether your domain is ready to send. They don’t measure what happens after you launch your campaign.

The real test of a successful warmup is whether your cold emails generate opens, replies, and conversations. We’ve worked with teams where strong warmup numbers didn’t translate to results because their team took too long to respond to interested prospects.

EmailAnalytics connects to Gmail and Outlook to measure your team’s email response time, email volume per rep, busiest sending hours, and conversation patterns. Pairing a warmup tool with EmailAnalytics gives you visibility into both deliverability and follow-up effectiveness.

Start Here: Your Email Warmup Checklist

1. Set up DNS authentication first. Configure SPF, DKIM, and DMARC records for every domain you plan to warm up. No warmup tool can overcome missing or broken authentication records.
2. Start warming 3 to 4 weeks before your campaign. Connect your email accounts to your warmup tool immediately after domain setup. The earlier you start, the stronger your reputation will be at launch.
3. Choose the right pricing model. If you’re warming 1 to 2 accounts, per-inbox tools like Lemwarm or WarmUp Inbox work fine. For 3+ accounts, switch to unlimited plans from Smartlead or SalesHandy.
4. Keep warmup running during campaigns. Don’t stop the warmup service once you start sending cold emails. Running warmup alongside your campaigns helps maintain your sender reputation through the organic engagement it generates.
5. Track follow-up performance. Sign up for a free EmailAnalytics trial to measure how quickly your team responds to replies. Speed of follow-up is the strongest predictor of cold email conversion.

Frequently Asked Questions

Do I really need to do email warmup?

Yes, if you’re sending cold emails from a new domain or rapidly scaling your volume. Without warmup, ESPs will flag your messages as spam. The process builds your sender reputation gradually by simulating real engagement like opens, replies, and inbox placement.

How long does it take to warm up an email address?

Most tools need 3 to 4 weeks of consistent activity to build sufficient trust. Some claim faster results in 2 weeks, but conservative timelines produce more stable reputations. Start warming at least 3 weeks before your first cold email campaign.

Can I warm up email inboxes manually?

Technically yes, but it’s extremely inefficient. You’d need to send emails from your new domain, have recipients open and reply, move messages out of spam, and mark them as important. This takes hours daily; automated tools accomplish the same result in minutes of setup.

Do I need to keep warming up my email inbox forever?

It’s strongly recommended. Running warmup alongside active campaigns helps maintain your sender reputation. If your cold emails aren’t generating enough organic engagement on their own, the warmup tool fills that gap and shields your domain from reputation decay.

Does email warmup guarantee better email deliverability?

Warmup significantly improves deliverability, but it’s not a standalone guarantee. You also need clean email lists, proper DNS authentication (SPF, DKIM, DMARC), well-written content, and reasonable sending volumes. Warmup builds the reputation foundation that makes everything else work.

What is the difference between per-inbox and unlimited warmup pricing?

Per-inbox pricing charges $12 to $69 per email account per month. Unlimited plans from Smartlead and SalesHandy cover all connected accounts under one flat fee. If you’re warming 3+ accounts, unlimited plans are almost always more cost-effective.

How do I measure the effectiveness of my email warmup?

Track your inbox placement rate, which measures what percentage of emails reach the primary inbox. Most warmup tools provide this metric. For post-warmup performance, EmailAnalytics connects to Gmail and Outlook to track response times, volume, and engagement patterns across your team.