6 Best Cold Email Account Warm Up Services

A speedometer with a rising needle representing a cold email account warm up service.

Think of your email sender reputation like a credit score. A brand-new account has no history, so email providers view it with caution. Sending a massive campaign from this account is like applying for a huge loan with no credit history—you’ll be denied. A cold email account warm up service is the tool you use to build that credit. It generates positive engagement by sending and receiving emails within a trusted network, slowly establishing a pattern of legitimate activity. This process proves your account is trustworthy, making it far more likely that your future outreach emails will be delivered successfully.

Key Takeaways

Treat Sender Reputation as Your Credit Score: A warm-up service is the best way to build this score from the ground up. It creates a history of positive engagement, signaling to email providers that you're a trustworthy sender whose messages belong in the primary inbox.
Automate the Foundation, Not the Relationship: Use a warm-up service to handle the technical job of building trust with email providers. Your job is still to send valuable, personalized content and stick to safe daily sending limits to maintain the reputation the service helped you build.
Safeguard Your Entire Domain's Health: Your sender reputation is tied to your domain, not just one inbox. A proper warm-up protects this critical business asset, preventing your outreach efforts from damaging the deliverability of all company emails, from sales to support.

What is an Email Warm-Up Service?

Think of a brand-new email account like a new phone number. If you suddenly started sending hundreds of messages from it on day one, you’d look like a spammer. Email service providers (ESPs) like Google and Microsoft view new email accounts with the same suspicion. An email warm-up service is a tool designed to build that trust for you. It automates the process of sending and receiving emails from your new account, gradually increasing the volume over time.

These services essentially simulate natural, human-like conversations to show ESPs that your account is legitimate and not a source of spam. By doing this, they help you build a positive sender reputation from the start. This is a critical first step for any cold outreach campaign because a good reputation is what convinces inbox providers to deliver your messages to your recipients' primary inboxes. Using a warm-up tool can supercharge your email deliverability and ensure your carefully crafted campaigns actually get seen. Without this foundational step, you risk having your emails automatically filtered into the spam folder, rendering your outreach efforts useless before they even begin.

Why Warming Up Your Email is Crucial for Deliverability

Warming up your email is all about building a good reputation. Every email address and domain has a "sender reputation," which is like a credit score for your email activity. Internet service providers (ISPs) use this score to decide whether your messages are trustworthy or if they belong in the spam folder. When you start sending from a new or inactive account, you have no history, so ISPs are naturally cautious.

A proper warm-up process establishes a positive sending history. It shows providers that you’re a legitimate sender who engages in genuine conversations. This helps your important messages land in people's main inboxes instead of getting lost in spam, which is the entire goal of your outreach efforts.

How Do Warm-Up Services Actually Work?

So, how does a tool magically make your account look trustworthy? It’s pretty clever. A warm-up service uses a large network of real, established email inboxes to interact with your account. The tool automatically sends emails from your address to inboxes within this network. Then, those accounts will automatically open your message, sometimes reply to it, and even mark it as important.

This mimics the behavior of a real person having genuine conversations. This positive engagement sends strong signals to email providers like Gmail and Outlook that your account is active and valued by others. Over time, this consistent, positive activity builds a solid sender reputation, making the provider more likely to deliver your future campaign emails directly to the primary inbox. The best services use an email warmup process that looks completely natural.

Busting Common Myths About Warm-Up Tools

If you’ve spent any time researching this topic, you’ve probably seen some skepticism. A common concern is that warm-up tools are a scam and that email providers can easily spot these automated interactions. Some people believe that since the emails are just going back and forth within a closed network, it’s an obvious trick.

While this might be true for low-quality services, reputable warm-up tools are far more sophisticated. They use advanced algorithms to randomize sending schedules, vary message content, and create human-like engagement patterns. This makes the activity look authentic. The key is that the network is made of real, aged inboxes with their own healthy reputations. As this Reddit discussion shows, results often come down to the quality of the service you choose.

Why Do You Need an Email Warm-Up Service?

If you’ve ever set up a new email account for outreach, you know the temptation to jump right in and start sending. But hitting "send" on a large campaign from a cold account is one of the fastest ways to land your messages in the spam folder. Email service providers like Google and Microsoft are naturally skeptical of new or inactive accounts that suddenly start sending high volumes of email—it’s a classic spammer tactic. This is where an email warm-up service becomes essential.

Think of it as a strategic first step. Instead of blasting out hundreds of emails on day one, a warm-up service gradually builds your account's credibility. It automates a process of sending and receiving emails, generating positive interactions that signal to providers that you're a legitimate, trustworthy sender. This process establishes a positive sending history, which is the foundation of good deliverability. Without it, your carefully crafted campaigns might never even reach your prospects' inboxes, wasting your time and effort before you even get started. It’s about playing the long game to ensure your outreach has a real chance to succeed.

How to Stay Out of the Spam Folder

The single biggest reason to use a warm-up service is to keep your emails out of the spam folder. These services work by mimicking human behavior to make your email account look trustworthy to internet service providers (ISPs). The platform automatically sends emails from your account to a large network of other inboxes. In return, it receives replies, and if any of your warm-up emails land in spam, they are automatically removed and marked as "not spam."

This positive engagement is critical. It trains the algorithms used by spam filters to recognize your emails as valuable and expected. Over time, this consistent, positive activity shows providers that real people are engaging with your messages, making it much more likely that your actual campaign emails will land directly in the primary inbox.

Build Your Sender Reputation from the Ground Up

Every email address and domain has a sender reputation, which is essentially a trust score that email providers use to evaluate your messages. A good reputation means your emails get delivered; a bad one sends them straight to spam or gets them blocked entirely. When you start with a new email account, you have no reputation at all. Sending a high volume of emails right away is a huge red flag that can instantly damage your score.

An email warm-up service helps you methodically build a positive sender reputation from scratch. By starting with a low volume of emails and gradually increasing it, the service establishes a pattern of reliable and legitimate activity. Each positive interaction—an open, a reply, a message moved from spam—contributes to your score, proving to providers that you're a sender worth trusting.

Protect Your Domain's Authority

Your sender reputation isn't just tied to a single email address; it's also connected to your entire domain. If emails from sales@yourcompany.com are consistently marked as spam, it can negatively impact the reputation of yourcompany.com as a whole. This is a serious risk, as a poor domain reputation can affect the deliverability of all emails sent from your organization, including critical messages from marketing, customer support, and even your internal teams.

Using a warm-up service is a proactive way to protect this vital business asset. By ensuring your outreach accounts establish positive sending patterns from the very beginning, you safeguard your domain's authority. This prevents your cold outreach efforts from unintentionally harming your company's overall email deliverability, ensuring all your communications continue to run smoothly.

Key Benefits of Using a Warm-Up Service

Using an email warm-up service isn't just a "nice-to-have"—it's a foundational step for any serious cold outreach strategy. Think of it as laying the groundwork before you build the house. Without a proper warm-up, your carefully crafted campaigns might never even reach their intended audience. The core benefits all circle back to one main goal: ensuring your emails get delivered and seen. By automating the process of building a positive sender history, these tools help you establish trust with email providers, protect your domain, and ultimately, get better results from your outreach efforts.

Land in the Inbox, Not in Spam

The most immediate and crucial benefit of a warm-up service is improving your email deliverability. When you send emails from a new or cold account, internet service providers (ISPs) like Google and Microsoft are naturally suspicious. A warm-up tool works to build trust by mimicking the behavior of a real, active user. It automatically sends emails to a network of other inboxes, generates replies, and even marks your messages as "important." This positive activity signals to ISPs that you're a legitimate sender, not a spammer. As a result, your emails are far more likely to land in the primary inbox where they can actually be read, instead of getting buried in the spam folder.

Improve Your Sender Reputation Score

Every email domain and IP address has a sender reputation, which is essentially a credit score that tells email providers how trustworthy you are. A low score means your emails are destined for the spam folder, while a high score grants you access to the inbox. A warm-up service systematically builds this reputation from the ground up. By generating consistent, positive engagement over time, it proves to providers that your sending habits are healthy and non-threatening. This is a proactive way to build a strong sender reputation before you even launch your first major campaign, setting the stage for long-term success and preventing deliverability issues down the road.

Lower Your Risk of Getting Blacklisted

Jumping into high-volume sending with a new email account is one of the fastest ways to get your domain or IP address blacklisted. Blacklists are real-time databases used by ISPs to identify and block sources of spam. Once you're on one, it can be incredibly difficult to get off, and your email deliverability will plummet across the board. Warm-up services help you avoid this nightmare scenario. They gradually increase your sending volume according to a safe, automated schedule. This slow and steady ramp-up demonstrates legitimate behavior, significantly reducing the risk of being flagged as a spammer and protecting your most valuable asset: your domain's authority.

See Better Engagement Over Time

Ultimately, the goal of warming up your account is to get better results from your cold email campaigns. When your emails consistently reach the inbox, every other metric improves. You'll see higher open rates because more people have the chance to see your subject line. You'll get more clicks because your call to action is actually visible. And you'll receive more replies because you're starting conversations instead of talking to a spam filter. By building a foundation of trust with email providers, a warm-up service ensures your outreach efforts aren't wasted. It’s the first step in a successful process that allows your great copy and compelling offer to do their job, which you can read more about on the ScaledMail blog.

The Best Cold Email Warm-Up Services

With so many options out there, picking the right warm-up service can feel overwhelming. The best choice for you really depends on your sending volume, budget, and technical needs. Some tools are built for simplicity and are great for solo entrepreneurs, while others offer robust infrastructure designed for high-volume agency work. To help you find the perfect fit for your cold outreach goals, I’ve rounded up six of the most effective and well-regarded services on the market. We'll look at what makes each one stand out, from the size of their inbox network to the depth of their analytics.

Each one offers a slightly different approach. Some use a massive, automated network of inboxes to simulate natural email activity, while others leverage a community-based model that relies on real user interactions. There are also comprehensive platforms that go beyond simple warm-ups to analyze every aspect of your deliverability, from domain health to email content. Understanding these differences is key to selecting a tool that not only gets your emails into the primary inbox but also protects your domain's long-term health. Let's explore the top contenders so you can make an informed decision for your campaigns.

ScaledMail - Dedicated infrastructure for high-volume campaigns

If you’re serious about sending a high volume of cold emails, you need more than just a basic warm-up tool—you need a solid foundation. That’s where ScaledMail comes in. We provide dedicated infrastructure designed specifically for large-scale campaigns, ensuring your emails are not only warmed up properly but are also delivered efficiently. This approach gives you maximum control and reliability, which is essential when your business depends on outreach. It’s the ideal solution for agencies and marketing teams who need a robust system that can handle thousands of emails without compromising deliverability or sender reputation.

Warmup Inbox - Network of real inboxes for authentic interactions

Warmup Inbox is a popular choice because it focuses on creating genuine-looking activity for your email account. The service uses a large network of real email inboxes to automatically send, open, and reply to your warm-up emails. This mimics human behavior, signaling to providers like Google and Outlook that your account is legitimate and trustworthy. It’s a straightforward and effective tool for anyone who sends cold emails, from sales teams to recruiters. The goal is to make your account look active and credible, which helps your actual outreach land in the primary inbox instead of the spam folder.

Lemwarm - Large network with a personalized warm-up approach

Created by the team behind Lemlist, Lemwarm is known for its massive network of over 10,000 real email accounts and its smart, personalized warm-up process. It doesn’t just send generic messages; it gradually increases sending volume and uses custom variables to make the interactions look more natural. Users often praise it for its easy setup and clear monitoring, which lets you track your progress and sender score over time. Lemwarm also includes features to detect potential threats to your deliverability, giving you an extra layer of protection as you build your sender reputation.

MailReach - Community-based warm-up effectiveness

MailReach takes a community-powered approach to warming up your inbox. It connects you with a network of other real users, creating a high-quality pool of inboxes to interact with. This method generates positive engagement—like opens, replies, and marking emails as "important"—that helps build a strong sender reputation. It’s known for being highly effective and has a solid reputation among users for delivering results. If you’re looking for a tool that leverages the power of a real, active community to improve your deliverability, MailReach is a fantastic option to consider.

TrulyInbox - Unlimited email accounts without extra fees

For those managing multiple email accounts, TrulyInbox offers a compelling advantage: you can connect an unlimited number of inboxes without paying extra, even on its most basic plan. This makes it an incredibly cost-effective solution for agencies or individuals running campaigns from several different domains. Beyond its pricing model, TrulyInbox is praised for its simplicity and effectiveness. It focuses on doing one thing well—warming up your email accounts—with a clean interface and reliable performance. It’s a great choice if you want a no-fuss tool that gets the job done without a hefty price tag.

Folderly - Comprehensive deliverability analysis and domain health checks

Folderly goes beyond standard warm-up features to offer a complete email deliverability service. While it does warm up your account, its real strength lies in its deep analytics. The platform helps you understand exactly why your emails might be landing in spam by checking your domain health, analyzing your email content, and monitoring blacklists. It’s a powerful tool for anyone who wants to take a proactive and data-driven approach to their email outreach. If you’re not just looking to warm up an inbox but want to master your overall deliverability, Folderly provides the comprehensive insights you need.

What to Look For in a Warm-Up Service

Not all warm-up services are created equal. When you're vetting your options, it can feel like you're comparing apples to oranges. To cut through the noise, focus on a few key areas that directly impact how effective the service will be for your campaigns. Think of it as a checklist to make sure you’re getting a tool that not only works but also fits seamlessly into your workflow. A good service does more than just send emails; it intelligently builds your reputation so you can focus on writing great copy and connecting with leads. Here’s what you should be looking for.

Network Size and Quality

The core of any warm-up service is its network of email inboxes. You want a service with a large and, more importantly, high-quality network of real accounts. These are the accounts that will be sending, opening, and replying to your emails to simulate genuine human interaction. This activity signals to providers like Google and Microsoft that your account is active and trustworthy, which is essential for building a positive sender reputation. A small or low-quality network with bot-like activity can do more harm than good, so always prioritize services that are transparent about the quality of their network.

Automation and Customization

A great warm-up service should save you time, not create more work. Look for strong automation features that handle the day-to-day process without constant oversight. The best tools go a step further by offering customization. You should be able to adjust the warm-up strategy to fit your specific needs, like setting the sending volume or the rate of increase. Some services even use AI to create personalized warm-up plans and craft unique email copy, making the interactions look even more authentic. This level of control helps you warm up your account efficiently and safely.

Performance Tracking and Analytics

You can't improve what you don't measure. A solid warm-up service must provide clear performance tracking and analytics. You need to see how your deliverability is improving and monitor your sender reputation over time. Look for a dashboard that gives you insights into your domain health and flags potential issues before they become major problems. Some services will even send you alerts if your reputation score drops, giving you a chance to pause your campaigns and address the root cause. This data is crucial for making informed decisions and ensuring your emails consistently land in the inbox.

Integrations and Ease of Use

Finally, consider the practical side of things. The tool should be easy to set up and integrate with your existing email accounts, whether you're using Google Workspace, Outlook, or another provider. A clunky interface or complicated setup process can kill your momentum. The goal is to find a service that feels intuitive from the start. Some platforms are specifically designed to be simple for anyone to use, regardless of their technical skill. Also, check if they allow you to connect multiple email accounts, as this can be a huge advantage if you manage several domains or campaigns.

How Much Do Email Warm-Up Services Cost?

When you're ready to add a warm-up tool to your outreach stack, the first question is usually about cost. The prices for these services can vary quite a bit, so it helps to know what to expect. Let's break down the typical pricing structures and figure out if the investment makes sense for your business.

Understanding Different Pricing Models

Email warm-up services don't have a standard price tag. You'll find affordable options starting around $15 to $25 per month for a single email account, which is great if you're just starting out. More advanced platforms can run much higher, especially if they include detailed analytics and support for a large team. Most services use a "per-inbox" model, meaning the price you pay is tied directly to the number of email accounts you need to warm up. For example, a service might charge a flat fee like $19 per email inbox per month. This is the most common structure, so as you compare options, pay close attention to how each one handles multiple accounts.

How to Budget for a Warm-Up Service

Budgeting for a warm-up service starts with a simple question: How many inboxes are you using for your outreach? Since most tools charge per account, your total cost will scale with the size of your operation. If you have a team of five sales reps, each with their own email address for outreach, you'll likely need to budget for five "seats" or inboxes. When you're comparing services, look for clear and transparent pricing. You want to know exactly what you're getting for your money without any surprise fees. Check out a few pricing pages to get a feel for how different companies structure their plans and find one that aligns with your campaign goals.

Is It Worth the Investment?

Spending money on a service that just sends emails back and forth might seem counterintuitive, but it's one of the smartest investments you can make in your outreach strategy. The core job of a warm-up tool is to build a positive sender reputation for your domain and email accounts. This reputation is what tells providers like Google and Microsoft that you're a legitimate sender, not a spammer. Without a proper warm-up, your carefully crafted emails have a much higher chance of landing in the spam folder, where they'll never be seen. When you think about it that way, the monthly fee is a small price to pay to ensure your messages actually reach their destination.

The Potential Downsides of Warm-Up Services

While email warm-up services are a go-to tool for many marketers, they aren't a perfect solution. It's smart to go in with a clear understanding of the potential drawbacks before you commit. Relying on these services without a solid strategy can sometimes create more problems than it solves. From questions about their actual effectiveness to the costs involved and the dangers of over-automation, there are a few critical points to consider. Thinking through these potential issues will help you make a more informed decision and set your campaigns up for long-term success. Let's look at some of the common concerns.

Do They Really Work? (And Can You Get Caught?)

It’s a fair question, and one that comes up often in marketing forums: do these tools actually work, or are they just smoke and mirrors? The honest answer is, it depends on the service. A high-quality warm-up tool uses a network of thousands of real, established inboxes to generate positive interactions, signaling to providers like Google and Microsoft that you're a legitimate sender. However, email service providers are constantly getting smarter at detecting artificial engagement. If a service uses a low-quality network or predictable, robotic patterns, your account could get flagged, defeating the entire purpose. The key is to choose a service that creates authentic-looking activity to effectively build your sender reputation.

The Cost and Time Commitment

Warming up your email accounts isn't free, and it isn't instant. Most services charge a monthly fee per inbox, which can add up quickly if you're managing multiple accounts for your outreach campaigns. You're typically looking at a recurring investment, so it's important to factor that into your budget. Beyond the financial cost, there's also a significant time commitment. A proper warm-up process doesn't happen overnight; it can take several weeks of gradually increasing sending volume to establish a positive reputation. This requires patience and careful planning, as you won't be able to launch a full-scale campaign from day one. You need to see this as part of your overall infrastructure pricing and strategy.

The Risk of Relying Too Much on Automation

Automation is a powerful tool, but a "set it and forget it" approach to email warm-ups can be risky. These services are designed to supplement, not replace, good sending practices. If you successfully warm up an account only to blast out poorly written, spammy emails, your sender reputation will plummet anyway. Your content quality, personalization, and list hygiene are still the most important factors for deliverability. Think of a warm-up service as a tool that gets your foot in the door. It’s still up to you to be a good guest by sending valuable emails that people actually want to read and engage with.

How to Choose the Right Warm-Up Service for You

Picking the right warm-up service feels a lot like choosing a business partner. You need someone reliable, effective, and easy to work with. With so many options out there, it’s easy to get overwhelmed. The key is to cut through the noise and focus on what truly matters for your specific outreach goals. It’s not about finding the "best" service in a vacuum, but the best one for you.

Think about your daily sending habits, the tools you already use, and the level of support you’ll need if things go sideways. By evaluating services based on these core needs, you can find a tool that seamlessly integrates into your strategy and sets your campaigns up for success. Let’s break down the three most important factors to consider.

Figure Out Your Sending Volume

First, you need to get a handle on your sending volume. If you’re planning to send a high number of cold emails, internet service providers (ISPs) like Gmail and Outlook are more likely to flag your account as suspicious. This is where warming up becomes essential. The process helps you build a positive sender reputation from day one, proving to ISPs that you're a legitimate sender. A good warm-up service automates this process, gradually increasing your sending volume to establish trust and ensure your emails land in the main inbox, not the spam folder.

Match the Features to Your Workflow

Next, look at the features and make sure they align with your workflow. Some services are straightforward—they just warm up your email, and that’s it. Others offer a more comprehensive suite of tools, including domain health checks, email content analysis, and detailed analytics. Consider what you actually need. If you already have tools for A/B testing and content analysis, a simple warm-up tool might be enough. But if you’re looking for an all-in-one solution to manage your deliverability, a more feature-rich platform is the way to go. The goal is to find a service that complements your process, not complicates it.

Check for Great Support and Reliability

Finally, don’t overlook support and reliability. While cost is always a factor, a cheap service with non-existent customer support can cost you more in the long run. When a campaign hits a snag, you need a responsive team you can count on to help you troubleshoot. Look for services with a reputation for solid support and consistent performance. Before you commit, see if you can book a call or talk to a real person. Investing in a reliable service with great support is an investment in your campaign’s success and your own peace of mind.

Best Practices for a Successful Warm-Up

Using a warm-up service is a fantastic first step, but it’s not a magic wand. To get the best results and build a sender reputation that lasts, you need to pair the tool with smart strategies. Think of it like training for a marathon—you can’t just show up on race day and expect to win. It requires a consistent, thoughtful approach. By following a few key best practices, you can ensure your warm-up process is effective and sets the stage for long-term campaign success, keeping your emails where they belong: in the inbox.

Start Slow: How to Increase Volume Gradually

Patience is your best friend during the warm-up phase. The whole point is to mimic the behavior of a real person who just opened a new email account. You wouldn't send hundreds of emails on day one, and your warm-up process shouldn't either. By slowly increasing the volume of emails sent, you build trust with email providers and show them you're a legitimate sender. When you eventually start sending your cold email campaigns, they’re more likely to land in the primary inbox instead of getting flagged as spam. A sudden, high-volume blast is one of the fastest ways to get your account suspended. Let the warm-up service do its job by gradually ramping up activity over several weeks.

Set Daily Limits to Stay Safe

Once your account is warmed up, it’s tempting to open the floodgates. Resist that urge. Maintaining a good sender reputation means sticking to reasonable daily sending limits. A good rule of thumb is to keep the number of cold emails you send from each email account to less than 40-50 per day. This isn't about limiting your outreach; it's about scaling it sustainably. If you need to send more, the answer isn't to push one account to its limit. Instead, you should scale your outreach by adding more warmed-up accounts to your rotation. This approach protects each account's reputation and ensures your entire operation remains healthy and effective.

Play the Long Game to Build Your Reputation

Think of your sender reputation as a credit score for your email account. Every action you take either builds it up or tears it down. Warming up your email is how you start building a good reputation, which helps your important messages land in people's main inboxes. But the work doesn't stop there. Consistently sending high-quality, personalized emails that get positive engagement (opens, replies) will continue to strengthen your reputation over time. On the flip side, high bounce rates and spam complaints will quickly undo all your hard work. The goal isn't just to warm up an account; it's to maintain its stellar reputation for the long haul.

Frequently Asked Questions

How long does it take to properly warm up an email account? There's no magic number, but you should plan for the process to take at least a few weeks. A proper warm-up is gradual by design, starting with just a handful of emails and slowly increasing the volume over time. This methodical pace is what makes your activity look natural to email providers. Rushing it is one of the fastest ways to get your account flagged, which is the exact opposite of what you want to achieve.

Can I just warm up my email account myself without a tool? While you technically could try, it would be an incredibly inefficient and time-consuming task. To do it effectively, you would need to manually send, receive, and reply to emails from a large network of established, high-reputation inboxes every single day. A warm-up service automates this entire process, leveraging its existing network to create consistent, positive engagement that would be nearly impossible to replicate on your own.

Do I need to keep the warm-up service running after my account is ready? It's a smart move to keep the service running, even at a lower intensity, alongside your live campaigns. Your sender reputation isn't a one-and-done achievement; it requires ongoing maintenance. A continuous warm-up provides a steady stream of positive interactions that helps offset any negative signals from your outreach, like bounces or unsubscribes. This keeps your reputation stable and your deliverability high in the long run.

Can a warm-up service fix a domain that already has a bad reputation? A warm-up service can be a powerful part of the recovery process, but it can't single-handedly fix a severely damaged reputation. If your domain is already struggling with deliverability or is on a blacklist, your first step is to identify and fix the root cause. Once you've addressed the underlying issues, a warm-up tool can help you methodically rebuild trust with email providers by establishing new, positive sending patterns.

Is it safe to give a third-party service access to my email account? This is a completely fair question, and security should always be a priority. Reputable warm-up services use secure authentication methods, like OAuth, which grant them permission to send emails on your behalf without ever seeing or storing your actual password. Always choose a well-established provider with a strong reputation for security to ensure your account and data are protected.