How to Use an Email Warmup Tool in Your Cold Email Strategy + 9 Tools for 2024

You’ve spent time and energy on the cold emails you’re sending. If they get sent to spam, that effort is wasted. All those prospects that could turn into valuable leads for your sales team to turn into customers? Lost. That's where email warmup tools come into play.

Avoid wasted efforts by using an email warmup tool to set up a better domain reputation and get into inboxes (not spam boxes).

But how does this work in your cold email strategy? Which email warmup service is right for you?

Keep reading to improve your email deliverability and get your message to the right people every time.

Wondering how to achieve better open rates for your sales emails? Uncover the secrets of successful email deliverability through strategic technical email setup.

How Email Warmup Tools Improve Email Domain Reputation

When an email service provider sees sporadic, unusual sending activity from your email, they’ll be more likely to drop you in spam.

Like your credit score is a trust metric based on various factors, your email domain reputation tells email service providers whether they should trust you. This reputation is based on factors such as

  • Open rates
  • Bounce rates
  • Email engagement rates
  • Spam trap hits
  • Blacklistings
  • Domain age

An email warmup tool is a service that sends out emails regularly from your address, gradually increasing the number of emails and engaging with them, building up your email "credit score" and developing trust with service providers.

The goal: avoid the black hole of spam, get into the inbox, and get more replies to your cold emails.

How to Include an Email Warmup Service in Your Cold Emailing Strategy

Using the best email warmup tool for your business is only part of prepping your cold email campaign. Another crucial step is understanding how to create a reliable, user-friendly, and customized email account to meet your specific communication needs. Implementing these strategies will ensure that your domain reputation stays squeaky clean.

Want to improve your B2B cold email open rates? Check out our article on 12 B2B Cold Email Templates and discover how a well-optimized B2B cold email template can help.

Determine Your Domain Health

You can’t fix a problem until you know its root cause. So, start by checking the health of your email domain.

There are plenty of tools to do it, but why not go to the source? With a 22.8 percent market share, Gmail is one of the largest email service providers. With Google Postmaster tools, you can check your domain health using proprietary data from the beast itself.

With this tool, you can track:

  • Domain reputation (marked as bad, low, medium, or high)
  • IP reputation
  • Spam rate
  • Delivery errors

With these stats in mind, you’ll better know where to start improving (or maintaining) your domain health.

Keep Your Lead Data Clean

A high bounce rate is a warning sign to email service providers. If you’re using outdated B2B data for your email campaigns, you could send emails to nonexistent addresses and rack up a suspicious reputation.

Pro tip: Want to check bounce rates for a particular campaign? In Close’s Workflow Reports, you can monitor bounce rates for each sequence you create, and even dive into the specific leads that bounced. Be sure to clean up these bounced addresses so you don’t send them again in the future.



Another danger when it comes to your data is purchasing lists of leads. While this is a fast way to set up your email campaign, it’s certainly not the most effective—and it could lead to quickly ruining your email domain reputation. Instead, set up your own ideal customer profiles, then use prospecting tools like LinkedIn Sales Navigator or LeadFuze to discover leads that fit your profile.

Maintaining clean data in your CRM isn’t easy. But when you do, you’ll have a healthier domain reputation and higher engagement by sending to people who will actually receive your sales email.

In this context, leveraging AI can be a game-changer. Our AI Email Writer tool can help you craft effective emails that resonate with your audience, ensuring your messages are not just delivered but also read and acted upon. This tool uses advanced AI algorithms to understand your writing style and target audience, providing you with personalized suggestions for improving your email content.

Include an Opt-Out

Now, this may seem a bit counterintuitive, but hear me out. We’re used to seeing an "Unsubscribe" link at the bottom of a marketing email, but including that unsubscribe link in your cold email campaigns can help improve your reputation with email service providers.

Since most spam blasts don’t include an unsubscribe link, this is something service providers look for when determining whether an email is spam or not. Including it can help you get into the inbox you’re looking for.

Avoid Using "Spam Words" in Your Cold Emails When Possible

The golden rule of email etiquette is not to send spam, respecting the inboxes of others. Spam filters continue to grow more intelligent, so simply including words like "act now" or "free access" won’t land you in the spam folder.

That said, if you cram in a bunch of spam words (especially if they’re in ALL CAPS), you’re treading on thin ice.

Here are some potentially spammy phrases you may want to avoid:

  • You are a winner
  • No strings attached
  • Once in a lifetime
  • This isn’t spam
  • Cards accepted
  • You’ve been selected
  • 100% satisfied
  • Don’t delete

Warm Up Your Email Domain Before Sending Campaigns

Now, you might be thinking: hey, can’t I just warm up my email domain manually?

And you’d be 100 percent correct. But, do you really want to?

While warming up your email domain manually is possible, it takes a lot of time and effort, and may not have the same effect as a professional company that’s specialized in this.

So, use an email warmup tool to get your domain prepared and start sending more emails at a time.

In short, an email warmup tool should be part of your strategy to boost domain reputation—but it’s not the whole package. When you combine this with a whole healthy email strategy, you’ll be in good shape to stay out of spam.

That said, which email warmup service should you choose?

The 9 Best Email Warmup Tools to Use in 2024

Looking for the right email warmup service for your business? Let’s discuss these 9.

First, we’ll see 4 dedicated email warmup tools; then we’ll look at some email-sending services that include email warmup features.

1. Allegrow

email warmup tool reporting Allegrow

An up-and-comer in the world of email deliverability, Allegrow works to improve your sender's reputation by simulating real human conversation via email.

They’ll send emails from your address to Allegrow emails, then remove them from the spam folder and mark them as important. Then, they’ll interact and engage with your emails to improve your email reputation.

While this is happening, you can check the stats on their interactive dashboard to see how your email domain reputation is improving over time.

🔥 Best feature: No-code integration with Close CRM

💰 Price: Allegrow's pricing is available upon request and caters to different needs: the "Audit" tier is free for basic deliverability services, while the "Premium" and "Scale Plus" tiers offer advanced features for small and large teams, respectively, with detailed pricing provided on inquiry.

2. Warmbase

How to Use an Email Warmup Tool in Your Cold Email Strategy - Warmbase

‎A good option for small businesses looking to start their first cold email campaigns, Warmbase gives you 50 emails per day and multiple warm-up options for your email domain.

🔥 Best feature: Ability to warm up with almost any email service provider

💰 Price: $9 per email for 50 emails per day

3. Warmbox

email warmup service Warmbox

This email warmup tool uses AI and GPT-3 technology to send realistic emails and responses and improve your email domain health. You’ll also get detailed reports and analytics to see how things are going.

🔥 Best feature: Multiple warmup options, including progressive growth, flat, randomization for testing, or a custom plan

💰 Price: Starts at $15 per month for one inbox and 50 emails per day

4. GMass

How to Use an Email Warmup Tool in Your Cold Email Strategy - GMass

‎Our first free email warmup tool on this list, GMass, is a basic service that works well for Gmail or Google Workspace users. You can get started with just one click, and GMass will automatically detect what your daily volume and ramp-up should be.

Since this tool works directly inside Gmail, it’s best for small businesses that are sending their cold email sequences directly from their Gmail account.

🔥 Best feature: Multi-message threads to make email threads seem more natural

💰 Price: GMass offers three pricing tiers: "Standard" at $25/month, "Premium" at $35/month, and "Enterprise" at $55/month, each providing a range of features tailored to different email marketing needs, with detailed pricing openly available.

Now that we’ve discussed dedicated warmup tools, let’s talk about other email tools that include an email warmup feature:

5. Lemwarm

lemwarm email warmup dashboard

As one of the first email warmup tools ever to appear on the scene, we had to give Lemwarm a mention here. From the creators of the outbound sales email tool, Lemlist comes a tool that acts as a mailbox network for reliable warmups, connecting their clients and using all the domains in their platform to share and improve domain reputation.

🔥 Best feature: Lemwarm creates interactions between real email addresses from other users of their platform instead of using fake accounts to generate engagement with your emails

💰 Price: Starts at $32 per month, billed annually.

6. QuickMail AutoWarmer

How to Use an Email Warmup Tool in Your Cold Email Strategy - Quickmail

‎Another free email warmup tool option, the AutoWarmer from QuickMail gives you automatic unspam, auto-replies and engagement, and a gradual volume increase to your emails.

🔥 Best feature: Uses business language in automatic engagement emails from your domain instead of alternative language

💰 Price: Starts at $49 per month.

7. Email Warmup from

email warmup from

Sales engagement platform has a built-in tool for email warmup to build or even repair your email domain reputation.

Reply uses a network of peer-to-peer sending for the best results and automates positive engagement with your emails. You don’t even need to use their email service to get this feature; you can purchase it as a standalone service.

🔥 Best feature: Choose between GPT-3 email copy or your own email templates for warmup

💰 Price: Paid plans start at $49 per user/month.

8. Warm Up Your Email by Mailshake

How to Use an Email Warmup Tool in Your Cold Email Strategy - Mailshake

‎This handy tool from Mailshake offers a quick and easy email warmup service. Their team reviews your engagement emails and provides positive interactions.

🔥 Best feature: Analytics for your spam score and spam pattern

💰 Price: Starts at $29 per month with a maximum of 50 positive engagements per day

9. Woodpecker

How to Use an Email Warmup Tool in Your Cold Email Strategy - Woodpecker

‎Cold email automation tool Woodpecker is a good basic tool for someone just starting cold emailing. Aside from being an email warmup tool, Woodpecker’s cold email platform includes a deliverability monitor and bounce shield and also gives you helpful insights.

🔥 Best feature: AI-powered interest level monitor for cold emails

💰 Price: Woodpecker's pricing for their Cold Email service starts from $29 per month. This plan includes 500 contacted prospects, free email warm-up and verification tools, unlimited team members and email accounts, various campaign automation options, and A/B testing.

What's Next? Choose the Best Email Warmup Tool for You and Get Started

In the list above, you'll probably find more than one tool that catches your eye. To choose the right one, ask questions like:

  • Does this email warmup tool connect easily with my email service provider or other tools I use?
  • Does it fit my budget?
  • Does it give me the warmup options that my business needs?

Once you find the right tool, you're ready to start warming up your domain and getting your cold email strategy started.

New to cold emails? Get the book on cold emails from Close CEO Steli Efti:

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