Cold outreach without proper email warmup is like showing up to a black-tie event in flip-flops. You might get through the door, but you're definitely ending up in the spam folder.

Email warmup tools simulate human activity to build your sender reputation before launching campaigns. The right tool can mean the difference between 90% inbox placement and watching your emails disappear into the digital void.

Here's what we'll cover:

• Quick comparison table of the 7 best email warmup tools
• Step-by-step warmup workflow to get started fast
• Expert tips for choosing the right solution for your needs

TL;DR: 7 Best Email Warmup Tools

What Is Email Warmup and Why Is It Critical?

Email warmup is the process of gradually building your sender reputation with email service providers (ESPs) like Gmail and Outlook. Think of it as earning street cred with the email bouncer before you start sending at scale.

Without warmup, your cold emails hit spam filters faster than a telemarketer at dinnertime. ESPs see a new domain sending hundreds of emails and immediately flag it as suspicious.

The result? Your carefully crafted outreach campaigns land in spam folders, your reply rates tank, and your domain reputation gets torched.

Here's the thing: Once your domain is marked as spam, recovery is brutal. It's easier to prevent the problem than fix it later.

If you’re struggling with emails going to spam, check out our guide on why your cold emails are going to spam for the full breakdown.

How Email Warmup Tools Work (And What to Look For)

Email warmup tools simulate human activity by sending emails between real inboxes, opening messages, clicking links, and generating replies. This creates positive engagement signals that ESPs use to evaluate your sender reputation.

Core functions include:

• Gradual volume ramping – Starting with 5-10 emails daily and slowly increasing
• Engagement simulation – Opens, clicks, replies, and conversation threading
• Deliverability monitoring – Tracking inbox vs. spam placement rates
• Technical health checks – SPF, DKIM, DMARC validation and blacklist monitoring

Warmup Tool Features Checklist

The best tools combine large, high-quality networks with smart automation and detailed reporting. Avoid tools that rely on fake accounts or template-based interactions—ESPs are getting smarter at detecting these patterns.

If you want to skip the technical headaches and get straight to results, check out our cold email setup.

The 7 Best Email Warmup Tools

Let's break down each tool with real-world insights, pricing, and what makes them unique.

1. ListKit (Fully Managed, Private SMTP/IP Warmup)

ListKit isn't just another SaaS warmup tool—it's a fully managed cold email infrastructure that includes private SMTP warmup as part of a complete solution.

Key features:

• Private, pre-warmed inboxes + private SMTP delivered as a DFY cold email infrastructure with step-by-step onboarding
• Pre-warmed and health-monitored inboxes for maximum inbox placement from day one
• Full authentication setup with SPF, DKIM, DMARC configured by experts
• Deliverability specialist support for DNS setup, script writing, bounce diagnostics, and sending optimization
• Continuous monitoring with inbox placement tracking, alerts, and weekly performance reports
• No export limits for unlimited scaling
• Structured launch timeline: Week 1—domain/inbox config; Week 2—warmup/testing; Week 3—campaign launch; Ongoing—optimization

Pros and Cons

ListKit offers a 7-day free trial, pricing starts at $97/mo

ListKit’s impact: When Bailey needed to scale cold outreach to 1.25M+ emails/month, ListKit's managed warmup and private IPs kept reply rates high and bounces low.

See how ListKit enabled 1.25M cold emails monthly.

2. MailReach

MailReach focuses on authentic engagement through a network of 30K+ real business inboxes, primarily Google Workspace and Office 365 accounts.

The platform focuses on genuine engagement signals rather than simulated activity, with rigorous deliverability diagnostics. Perfect for SaaS companies running targeted outreach to decision-makers who need authentic engagement patterns to avoid spam filters.

Key features:

• Machine learning-powered warmup engine with variable send times and reply formats
• Inbox placement diagnostics via Spam Test (+ API to automate)
• Robust monitoring with alerts and Slack/API integrations
• Scalable pricing with volume discounts

Pros and Cons

MailReach pricing starts at $19.50 per mailbox per month

3. Warmy.io

Warmy.io uses AI to adjust warmup strategies in real-time, making it ideal for teams managing multiple clients or complex sending scenarios.

The platform offers advanced customization and high-volume capabilities with agency-focused features like white-labeling and client grouping.

Key features:

• AI-powered volume and behavior adjustment based on real-time performance
• High-scale operations supporting up to 5,000 emails/day per inbox
• White-label dashboards for agency client management
• Technical audits including SPF, DKIM, DMARC validation
• Advanced grouping and DNS/blacklist monitoring

Pros and Cons

Warmy.io pricing is not public

4. Lemwarm

Lemwarm integrates seamlessly with Lemlist campaigns while providing detailed analytics on inbox placement across different email providers.

The platform features an apps inbox placement across providers with detailed ESP-specific reporting, ideal for Lemlist ecosystem users.

Key features:

• 20K+ inbox network with peer-to-peer engagement
• Seamless Lemlist integration for campaign-specific warmup
• Automated warm-up with smart sending logic; deliverability tips/monitoring

Lemwarm pricing starts at $29/email/mo

Pros and Cons

5. WarmUp Inbox

WarmUp Inbox offers straightforward automation at an affordable price point. Its simplicity and low cost make it ideal for solo senders or early-stage businesses.

Key features:

• Basic automation with opens, replies, and conversation simulation
• Provides simple, automated warm-up through a 30k+ real-inbox network
• Multiple provider support (Gmail, Outlook, SMTP)
• Quick setup with free trial available

Pros and Cons

Warmup Inbox offers a 7-day free trial, pricing starts at $19/mo

6. Folderly

Folderly positions itself as a complete deliverability solution with warmup as one component of broader email health management. It’s ideal for enterprise-level email operations.

Key features:

• Automated inbox placement tests with reports across major providers
• IP insights and domain health checks
• Warmup tool to improve sender reputation and fix deliverability issues
• Real-time mailbox health monitoring
• End-to-end deliverability consulting and audits

Pros and Cons

Folderly pricing offers a free plan with 2 tests per month, pricing starts at $79/mo

7. Smartlead

Smartlead combines unlimited warmup with campaign automation, offering a consolidated platform for both functions.

It’s a one-stop platform merging outreach and warmup, despite trade-offs in specialized deliverability features.

Key features:

• Unlimited email warmup on all paid plans
• Campaign integration with auto rotation across sender accounts/domains
• Unified/master inbox and analytics for campaign management
• AI-driven warmup conversations (reply simulation)

Pros and Cons

Smartlead offers a 14-day free trial, pricing starts at $30/mo

Step-by-Step: How to Warm Up a New Email Account

Here's the proven 5-step workflow that works regardless of which tool you choose:

Step 1: Configure Authentication Records (Week 1)

Set up SPF, DKIM, and DMARC records in your DNS. These authenticate your emails and prevent spoofing.

Pro tip: If technical setup isn't your thing, ListKit's deliverability specialists handle all DNS configuration as part of their managed service.

Step 2: Start Small (Days 1-7)

Begin with 5-10 warmup emails per day to your most engaged contacts. Focus on simple, personalized messages that encourage genuine replies.

Common mistake: Jumping straight to 100+ emails daily. ESPs will flag this as suspicious behavior.

Step 3: Gradually Increase Volume (Weeks 2-3)

Double your daily volume each week if engagement remains positive. Monitor bounce rates and spam placement closely.

Timeline example:

• Week 1: 5-10 emails/day
• Week 2: 20-40 emails/day
• Week 3: 80-150 emails/day

Step 4: Monitor Key Metrics

Track inbox placement rates, open rates, reply rates, and spam complaints. Most warmup tools provide dashboards for this.

Red flags to watch:

• Bounce rate above 5%
• Spam complaints above 0.1%
• Sudden drops in open rates

Step 5: Scale to Full Volume (Week 4+)

Once your domain shows consistent positive engagement, scale to your target sending volume. Continue monitoring and adjust if issues arise.

Pro tip: Keep warmup running even after reaching full volume. Consistent engagement signals maintain your reputation long-term.

Looking for proven follow-up sequences? Check out our cold email follow-up templates to maximize your warmup investment.

Skip the Warmup Headaches With ListKit

Email warmup tools are essential for cold outreach success, but they're just one piece of the puzzle. You still need quality leads, compelling copy, and proper technical setup.

The right setup depends on your goals, volume, and stack. Managing warmup, lead generation, and campaign execution across multiple tools gets messy fast. That's why we built ListKit's fully managed infrastructure to handle everything.

From Triple-Verified leads to private SMTP warmup, so you can focus on closing deals instead of troubleshooting deliverability issues.

Need help with email verification too? Our guide to the best email verification tools covers the top options for cleaning your lists.

Common FAQs About Email Warmup Tools