11 Best Email Warm-Up Tools for Agencies, SDR Teams & Startups

If your cold emails are landing in spam, getting ignored, or suddenly seeing lower open rates than usual, you could have a bad email sender reputation.

Even the best outreach campaigns can fail when inbox providers like Gmail and Outlook don’t trust your domain.

Sending too many emails too quickly, using a brand-new domain, or having poor engagement rates can mess up your deliverability, making it harder for prospects to ever see your emails.

This is where using email warm up tools can help.

Email warm-up services are built to gradually build your sender reputation by automatically sending emails, generating replies, marking messages as important, and creating positive engagement signals.

The goal is simple: These tools help your messages land in the inbox and not in the spam folder.

In this article, we’ll share some of the best email warm-up tools (we even use some at our agency), and compare them, with pricing and reviews.

Do email warm-up tools still work?

At SalesBread, we’ve tested a few warm-up platforms across client domains and outreach campaigns.

While warm-up tools can help improve sender reputation, we’ve found that domain setup, list quality, and sending personalized, relevant emails have a better impact on deliverability in the long run.

And yes, if you are sending mass emails in 2026, you need warm-up tools. They do still work and help so that your emails don’t end up in the spam folder.

Who Should Use Email Warm-Up Tools?

Email warm-up tools are great for businesses and professionals who send cold emails at scale.

If you’re using a brand-new email domain, launching outbound campaigns, or struggling with poor deliverability, warm-up tools can help build trust with inbox providers like Gmail and Outlook before you send more emails.

Here are the main groups that would find email warm-up software useful:

Sales Teams and SDRs

Outbound sales teams often send hundreds of cold emails every week. Without proper warming, inbox providers may flag this activity as suspicious, meaning that your emails may land in spam folders instead of prospects’ inboxes.

Lead Generation Agencies

Agencies managing outreach for many clients work with several domains and inboxes at once. Email warm-up tools help protect sender reputation and reduce the risk of domains getting burned.

Startups and Founders

New companies often buy fresh domains for cold outreach. Since new domains have little to no sender reputation, warming them up slowly can help improve deliverability before scaling campaigns.

Recruiters

Recruiters sending a ton of outreach to candidates can also find warm-up tools helpful. These tools can help you keep a good sender reputation and avoid landing in spam.

Businesses Recovering From Poor Deliverability

If your open rates suddenly dropped, replies slowed down, or your emails started landing in spam, an email warm-up tool might be able to help rebuild sender trust over time.

Anyone Scaling Cold Outreach

The more emails you send, the more important your sender reputation becomes. You want to end up in the inbox and not spam, especially as your campaigns ramp up.

That said, email warm-up alone won’t fix deliverability issues caused by bad prospect lists, spammy copy, or incorrect DNS setup.

The best results usually come from a mix of email warm-ups, good cold email practices, and proper domain setup.

Best email warm-up tools comparison table

1. Snov.io

Snov.io Warm-up is an intuitive and fully automated email warmup tool designed to help your emails land in the inbox instead of spam.

Once connected, it gradually increases your sending volume and engages your email account in natural interactions; Opening, replying, bookmarking, and even rescuing messages from the spam folder, just like a real person would.

All warmup activity happens in a secure network of real inboxes, and these messages are automatically filtered from your main inbox so they won’t clutter your workflow.

The best part about Snov.io Warm-up is that it’s built right into the Snov.io ecosystem, so you can combine warmup with lead generation, outreach, and email tracking in one place.

Pricing

Snov.io, starts at $29.25 per month for their starter package and works its way up to a custom plan, but their next plan up is $74.25 per month and includes unlimited seats.

Reviews

According to G2, Snov has a 4.6-star rating. Many users mentioned that they found the tool easy to use and that customer support was really helpful. 

2. InboxAlly

InboxAlly is an advanced email deliverability tool designed to help businesses and marketers ensure their emails land in the primary inbox instead of spam or promotions folders. It does this by simulating real user engagement, such as opening emails, replying, and marking them as important.

InboxAlly takes a proactive approach by directly influencing inbox placement through AI-driven behavior modeling and customized warm-up sequences.

This “teaches” email providers to trust your messages, improving overall deliverability rates and sender reputation more effectively than traditional warm-up methods.

Pricing:

InboxAlly offers several pricing tiers to accommodate different needs.

The Starter Plan begins at $149 per month for up to 100 daily seed emails, while the Plus Plan costs $645 per month for up to 500 daily seed emails.

For larger senders, the Premium Plan is priced at $1,190 per month with additional support and strategy sessions.

Businesses requiring high-volume solutions can opt for a Custom Enterprise Plan, with tailored pricing available upon request.

Reviews:

InboxAlly has a rating of 4.6 out of 5 according to G2.

Many highlight its ability to improve deliverability and inbox placement significantly. One user shared their experience:

3. Warmup Inbox

Warmup Inbox is a very simple and effective email warmup tool that works just the way it is supposed to.

It connects your inbox to a network of inboxes talking to each other and recreates the way a typical person would interact with an email address. This includes replying to the emails, marking them as important, or, if needed, taking them out of the spam folder.

The whole process is automated and the “warmup” emails are filtered so it doesn’t affect the functionality of your inbox in any way.

The great thing about Warmup Inbox is that it uses a network of real inboxes.

Pricing

Prices range from $15 per month per inbox to $139 per month.

Each plan has different perks.

There is also a free trial, which will help you get a feel for the tool.

Reviews

According to G2 Warmup Inbox has a 4.7 star rating out of 5.

This is what one user had to say:

4. QuickMail.io

Quickmail offers a free auto warmer that will increase deliverability rates.

This is how QuickMails auto warmer works:  “Once you’ve linked your email account with the QuickMail Auto Warmer, your email address will automatically start sending and receiving emails to and from other real people using the Auto Warmer.

When an Auto Warmer email is sent from your address, it will be automatically opened and replied to, in the same way, a real email to a friend or coworker would be engaged with.

If your emails ever get caught in the filter, they’ll be automatically marked as ‘not spam’ and moved to the primary inbox to reduce the chances of it happening again.

With time, you’ll be showing ESPs that you’re a trustworthy sender that sends and receives real emails, making them less likely to flag you as a spammer when you launch your email campaigns.” 

The best part? It’s for free. 

Pricing

QuickMail pricing offers Single Plans and Agency Plans.

The Single Plans range from $49 per month to $129 per month.

The Agency Plans range from $399 per month for the basic plan to $799 per month for the Expert Plan.

You would have to check out their pricing page to get more details, but what’s great, is that there is a free autowarmer with each plan. You can also try QuickMail out for free for either 14 days or 21 days.

Reviews

QuickMail has a 4.7-star rating according to G2.

This is what one user had to say about QuickMail.io:

5. Lemwarm

Lemlist was the first to come to market with an email warmup solution ( Lemwarm ).

What is Lemwarm? It is a simple cold email warm-up tool that also connects to their email platform.

With Lemwarm, you can decide how many emails per day you want to send, and the tool will start automatically sending and replying to emails. 

Pricing

There are two pricing packages available. The essential plan is $24 per month per email, and the smart plan is $40 per month per email for the yearly payment option. You also have the choice of paying monthly or quarterly with a 10% discount.

Reviews

According to G2, Lemwarm has a 4.5 star rating out of 5.

6. Mailreach

Mailreach is a cold email software that helps with email deliverability and ensures that your messages land in the inbox rather than the spam folder.

It works by gradually warming up your email account through automated interactions, improving your sender reputation and inbox placement.

Mailreach uses a process where real interactions between warm-up accounts help build trust with email service providers. By improving your email deliverability, it helps ensure that your email address maintains a high reputation, reducing bounce rates.

Pricing

Pricing for Mailreach works on a sliding scale. For example, if you want to warmup 1 mailbox it will cost you $25 per month. And if you have 40 mailboxes that need to be warmed up, it will cost you $18 per mailbox per month, with a total cost of $720 per month.

Reviews

Mailreach has a rating of 4.6 out of 5 according to G2.

Some users said it’s pretty pricey, but they love how easy it is to use.

7. Warmy

Warmy will get your email domain and IP address ready to use so that it can develop a positive sender reputation and increase email deliverability.

This tool is useful for a few reasons (which we will still discuss below) but interestingly it also allows a sender to avoid spam filters that have a bad reputation for your mailbox and website.

Pricing

There are 3 options.

• B2B senders

• B2C senders

• Custom plans

Warmy doesn’t share pricing on their site, so you would have to book a demo call to find out. There is a free trial though.

Reviews

Warmy has a 4.8-star rating out of 5 according to G2. This is what one user had to say:

8. Warmbox

Warmbox is an email warm-up tool designed to improve email deliverability and prevent messages from landing in spam folders. It gradually increases the sending volume of emails while interacting with them to build a positive sender reputation.

By automatically engaging with emails—opening, replying, and removing them from spam—Warmbox helps businesses and individuals maintain high inbox placement rates, ensuring their outreach campaigns are more effective.

Pricing

There are 4 pricing options to choose from. From $15 per month for 1 inbox warmup to $139 per month for 6 inbox warmups.

Reviews

There weren’t too many reviews online about Warmbox. But according to Product Hunt, Warmbox has a 4 star rating. Out of all the tools listed in the article, this is probably the one that was a least favorite. So be sure to check it out carefully before subscribing. There were a few mixed reviews.

9. Mailwarm

With Mailwarm you email address will automatically send dozens of emails to more than 50 000 of Mailwarms accounts, and then you will get replies too.

This will ensure that you get a good sender reputation. The Mailwarm dashboard is also super easy to use and will track your activities daily.

Mailwarm is made for agencies, recruiters, outbound sales teams, and even newsletter creators.

Pricing

Mailwarm pricing ranges from $69 per month to $479 per month if you pay yearly. You can also cancel at any time with no questions asked.

Review

Most Mailwarm users on G2 mention how easy it is to use and set up, but some users mentioned that it can get quite expensive.

10. Warm Up Your Email

Warm Up Your Email is a warm-up tool created by Mailshake. They have a real human team that will interact with your emails to encourage a good sender reputation. Their team will also take your emails out of the spam folder if necessary.

Warm Up Your Emails also has a spam pattern checker, which will help you analyze data over 10 days.

This will help you see if you are getting your emails into your readers’ inboxes and not the spam folder.

Pricing

Pricing is reasonable and starts at $29 per month, and works its way up to $99 per month.

Review

Warm Up Your Emails gets a 4.5-star review on G2. Some users mention that it is a good tool, but it only sends a limited number of warm-ups per day.

11. Woodpecker

Woodpecker uses AI to warm up your inbox through conversations. Woodpecker is also quite a bit cheaper than some other tools on this list, and you will receive replies from real accounts.
It’s also really easy to use and sends your emails from the spam folder to your inbox automatically.

Pricing

Woodpecker works on a sliding scale, with the cheapest option being $24 per month annually, and $6,666 yearly for the unlimited plan. There is a 14 day free trial, with no credit card required.

Review

Woodpecker also gets 4.5 stars on G2, and users mentioned that customer support is great, along with how easy it is to use and set up.

Frequently asked questions about cold email warm-up tools

What are email warm-up tools?

Auto warmers are pieces of technology that automatically send emails on your behalf to groups of recipients that will respond automatically. 

It tells spam filters that this “sender” has a good reputation, and this helps increase your email deliverability rate. 

These tools also:

• Generate positive engagement on your email account

• Boost the chances of your email landing in your prospect’s inbox

• Show service providers, like Gmail and Outlook, that you are a trustworthy sender. 

No one wants their well-written email to end up in the spam folder, firstly because spam emails are sometimes not even viewed. Or emails that are in spam are viewed as untrustworthy. If you want to avoid a bad sender reputation, then using an email warm-up tool will help you.

But besides all this, out of every 12,500,000 emails sent, spammers receive one reply. So you can see how this can affect your email outreach, especially if you are trying to find prospects for your business. 

Interestingly, spam emails have increased since 2020, and studies show that nearly 85% of all emails are spam. 

This is why sales teams choose to use warm-up services for their campaigns, as it can help with deliverability issues. 

How do email warmup tools work?

A bit of background information first…

You have an inbox with one of the email sender providers ( like Gmail, Microsoft, Yahoo, and Outlook ), and you are a person that people like to interact with. 

Historically speaking, a few years ago, you had two types of people. Those who were sending legit emails, contacting their friends or co-workers, so engagement was high.

Secondly, you have spammers. A spammer sends lots of emails. People ignore the emails and flag them as spam. 

But there was a missing middle ground.

A few years ago, for example, there were email automation tools such as Mailchimp and Active Campaign, but there wasn’t software for sales emails, particularly.

When it comes to sending out sales emails, you can send them to prospects without spamming them to test the waters. For example, if you have a list of prospects, you could always send them a few good emails to see if they would be interested in your product/service.

Of course, though, your email engagement will be way lower than if you’re contacting your friends or colleagues.

So there is a middle ground category, and if you are doing marketing emails badly,  no one will engage with you. Therefore, you will be perceived as a spammer. 

This is where a “deliverability booster” can come in handy so that the email service provider is not going to block your email.

So, in short, email warm-up tools fill this gap between good and bad emails received by sending emails to a controlled group of accounts, who reply automatically to your emails. 

This then tells email service providers that you have a “good” sender reputation; therefore, when you start sending out emails to prospects, your emails won’t be sent to spam immediately. 

( Remember, even if you use automation tools such as Zapier — or any other API to send email — if your emails look legitimate and are not “spammy,” then the email service providers won’t be able to tell if you are sending the emails out yourself or not.

Why?

Today, sending an email using 3rd party tools is commonplace. So spam filters can not ignore this type of sending when factoring in a sender’s reputation.)

How long does the warm-up process take?

Let’s say you have a brand new account and would like to start with cold outreach campaigns. 

How long would it take to warm up your email? 

( A word of caution, the answer can change. When it comes to tech, the answer is never solid. It’s fluid and can change with time. Google and Microsoft are not going to tell you that they are changing the game. Therefore, once it happens, the software will need to be updated. )

Here is the current answer:

All tests show that it can take roughly two to three weeks to warm up email inboxes. This depends, though, on the volume of emails that you intend to send.

A good auto-warmer should have a certain ratio between the number of emails you are sending that are totally cold and the number of emails you are sending through your auto-warmer. 

Remember, though, that this needs to happen slowly.

You could send out 10 emails per day, and then 10 emails through your auto warmer, and then ramp it up with two additional emails per day.

This gives you a 50/50 ratio.

But if you want to send 100 emails per day, you could have a ratio of 20/10, BUT it depends highly on how much engagement you get with your actual cold email activity. 

Remember, if you get good engagement rates, you only need a little bit of a boost. 

You can use a simple math formula for the right ratio.

For example, if you send 100 cold emails a day, you can then send 10-20 auto-warmed emails. 

What’s written in auto warmer emails?

Curious about what’s written in the emails? Is it just any old jumble of words?  Some auto warmers use random questions in emails, such as “Do you have a lighter?”

Others might list animal names, fruit, or vegetables.  

But this can seem quite random. You might worry that people monitoring emails at Google, for example, are keeping an eye out for things that don’t make sense, but we can’t be 100% sure of this. 

Quickmail.io, though, sends emails that include words or sentences from a cold email outreach book that they wrote. These words and sentences are constantly scrambled around. Therefore, every email is different. 

This makes sense, as it seems like proper sentences and a legitimate email about sales, and not just randomized words.

The funny thing about these sentences is that if you read them, it kind of makes sense, but also doesn’t at the same time. 

The important thing is not exactly what’s written in the email, but more that it’s a mix of words and sentences so that each auto-warmer is unique. This can trick bots and, in some cases, even real people. 

Can email warm-up tools fix a bad sender reputation?

What if your email domain has developed a bad sender reputation over time? Perhaps all your emails are getting flagged as spam or are sent straight to the spam folder? 

Can a mail-warmer get you off the blacklist? Or would you need to trash your domain name and set up a new one?

The answer is yes, email warm-up tools could help you.

How?

Well, there are two choices.

Step back and let the auto warmer do its thing

You could step back and just allow the auto warmer to do its thing. Increase engagement and deliverability.

This takes about a month minimum to reset your lousy domain reputation. But this would mean that you would need to take a break from email, and not everyone has this luxury unless you’re on vacation. 

Create a new domain

The second option is to create a new domain and warm up the email for 2-3 weeks.  Once your domain reaches the 30-day mark, you will be off that “new email” blacklist.

PRO TIP: If you can, stay away from “.co,” as this is often viewed as spammy. Instead, use “.com,” “.io,” or “.net,”

Remember to keep using your auto warmer. Even if your open rates and deliverability are higher, keep using the auto-warming tools. 

What are the cons of email warm up tools?

There are some drawbacks in the sense that not all auto warmers are as good as others. 

Many new companies out there might have great marketing pitches, but their tools are not as great as others. (We will mention some of the best auto warmers out there shortly.)

Another drawback is that email warmers will not solve all your deliverability problems. You still need to focus on sending quality emails that are not spam. Quality over quantity will keep your domain reputation on solid ground.

To warm up or not to warm up?

An auto warmer isn’t really needed if you have a great sender reputation and excellent deliverability.

But if you would like to make sure that your emails land in your prospect’s inbox, a warm-up tool could really up your game. 

Remember, though, that even if you have a warm-up schedule as a marketer, you can just send the same template to thousands of prospects. (Because this will still give you a bad sender reputation .) 

Always focus on the quality of your email and not quantity when sending to your email list, and if this is something that you are struggling with, give us a call.

If you need some outreach advice, hop on a free 15-minute strategy session with the founder of SalesBread, Jack Reamer. SalesBread specializes in generating 1 lead per day by using personalized LinkedIn outreach.