Warming up your email account before you send your cold email campaigns is one of the best ways to ensure your emails land in your recipients’ primary inbox.
There are a variety of dedicated cold email warmup tools that will generate positive engagement on your email account, so you’re probably wondering: do they work, and what’s the difference between all of them?
In this guide, I’ll explain how these warmup tools work, and show you some of the best tools on the market.
- Warming Up Your Email Address: Automated vs Manual Methods
- The 12 Best Cold Email Warm Up Tools In 2023
- Is An Email Warming Tool Essential For Cold Emailing?
- Can You Warm Up Your Email Manually?
- When Can You Turn Off Your Email Warming Software?
Let's dive in.
Warming Up Your Email Address: Automated vs Manual Methods
There are two main ways to warm up your email inbox.
The first method is to run the process manually. After setting up your new inbox, you’ll send emails to your coworkers, sign up to newsletters, reply to incoming emails, and generate completely natural engagement signals on your inbox.
You’ll slowly ramp up your email sending volume and over time, the main email providers like Outlook and Gmail will trust your account.
The second method is by using an email warm up tool, like the MailFlow Auto Warmer.
These tools help you automate the email warm up process by generating real daily activity on your inbox.
Every day, they’ll send a low-volume of emails to other users in their email warm up network, showing email service providers that you’re a trustworthy user and helping you improve your email deliverability.
The 12 Best Cold Email Warm Up Tools in 2023
1. Mailflow: Free, And Does It All
Before Mailflow, you could easily spend thousands of dollars per month just to warm up your email addresses.
With Mailflow, you can now warm up to 100 inboxes completely free. And it's not just the pricing that makes this tool great. After testing many warmup tools, Mailflow stood out as one of the best in terms of quality and features.
Let's dive into why Mailflow is the #1 email warmup tool out there.
Generate Real Engagement to Warm Up Your Email Address
Once you’ve linked your email account with Mailflow, your email address will automatically start sending and receiving emails to and from other real people using Mailflow.
You’ll choose how many emails you want to send per day, and the process will start.
When a Mailflow 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.
Mailflow emails are automatically removed from your primary inbox after being sent or received, so your inbox will stay organized throughout the process.
Get Accurate Reports on Your Inbox Deliverability Performance
You’ll see detailed reports into your inbox performance: how often you’re landing in the main inbox, the spam folder, or other folders like the Gmail Promotions tab.
When you see that your email domain is performing well and your daily emails are regularly landing in the main inbox, you know you’re ready to start sending your first cold email campaign.
You can also see how your emails are being received by the main inbox and email providers, including free Gmail, G Suite, free Outlook, and Office 365.
If you ever see emails being delivered to spam, you can take steps to solve the problem and ensure future campaigns get delivered to the main inbox.
Send Untraceable Emails
Artificial intelligence ESP filters are getting smarter every day, and unusual inbox activity is ever more likely to be noticed.
One such activity is the language you use in your emails. If the emails from your email warmup tool deviate from regular business language, that can get you penalized.
While some warmup tools send emails about animals, plants, and other random topics, Mailflow emails use business language that will blend in with your other emails and be undetected.
Another risk factor is the code attached to the emails by some tools for tracking purposes. Mailflow emails have a very low code footprint, making them very similar to emails sent manually from your own inbox.
Take Your Deliverability to the Next Level
If you want to go the extra mile when it comes to email deliverability, Mailflow offers a boarder set of features designed to help you monitor and further improve it.
On Mailflow's paid plans you can get access to SPF & DKIM configuration assistance, blacklist monitoring on up to 100 blacklists for all your domains, and a daily sender reputation tracker with various providers to help you decide whether to continue or slow down some of your email activity.
Another upcoming feature is a redirection & uptime monitor to make sure your cold outreach domains lead to a valid web page. The monitor will notify you if a page is broken so you can fix it immediately.
These tools go beyond email warmup and are created for those who want to scale their email outreach while continuing to have great deliverability.
Natively Integrated to a Powerful Cold Email Automation Platform
QuickMail is a powerful platform for sending cold emails. You can upload your sales prospects, craft personalized templates, and schedule your emails and follow-ups to send and land in your prospects’ inbox at the perfect time.
Mailflow is natively integrated into QuickMail so that you can see your Mailflow sender reputation score from your QuickMail dashboard.
As you increase the volume of emails you’re sending every day, you can regularly review your Mailflow sender reputation scores to ensure your emails are still being sent to your prospects’ main inbox and that you're maximizing the opportunities from every outreach campaign you send.
Who is it for: Agencies, sales teams, and anyone using cold email to engage with new clients
Powerful free tool to warm up your email address
Designed specifically for cold emailers
Engagement group made up of real people and real email addresses
Warm up additional team inboxes for free
Detailed deliverability reports to see where your emails are landing
2. Warmup Inbox: Good Solution, At A Price
Warmup Inbox is a standalone email warming software.
They use a network of real inboxes, and once you sign up, your account will start engaging with these other accounts using Warmup Inbox.
It works with all of the main email service providers, including Gmail and Outlook 365, as well as Yahoo Mail, Amazon SES, and other custom inboxes.
You can send 1,500 emails per month per inbox on the base pricing plan, and they recommend that you use the service for at least 45-90 days to fully warm up your inbox before sending any cold email campaigns.
Warmup Inbox also provides warm up analytics and reporting so you know how your account is performing.
It’s a good standalone solution, with the only downside being that it’s relatively expensive compared to other options we’ll look at.
Who is it for: Email marketers needing a standalone email warmup service
Pricing: Starts at $12 per month per inbox for 50 emails per day. $39 per inbox per month for 150 emails per day. $199 per inbox per month for 500 emails per day.
A clear overview of whether your inbox is ready with a ‘health score’
Email blacklist monitoring to see if email providers trust your inbox and sender reputation
Good range of features considering it’s more affordable than most other email warmup tools options in this guide
Capterra users report that it can take months to see deliverability improvements
Gets expensive if you need to warm up multiple cold email inboxes
Not part of a cold email platform ecosystem, so it’s an extra cost
3. Warmbox: If Pretty UI Is Your Thing
Warmbox is a standalone email warming tool with great UX & UI design.
It has all the basic ingredients of a good email warm up tool: integration with the main email service providers, a large network of inboxes, and clear deliverability reporting so you know where your emails are landing.
One of their unique offerings is the ability to use different warm up recipes that let you customize sending schedules. For example, you can choose to increase the volume of emails over time, set a randomized schedule, or create your own custom rules.
The pricing increases quickly as you add inboxes, so if you’re expecting to be sending emails from a few different accounts you may be better off with an option that supports collaborative teams by default, like MailFlow's Auto Warmer.
For a mid-range price, Warmbox is nonetheless a good option to help keep your emails out of the spam folder.
Who is it for: Individuals or teams doing regular cold outreach
Pricing: Starts at $15 per month for 1 inbox, $69 per month for 3, $139 per month for 6. Unfortunately, there are no discounts for adding more inboxes.
Ongoing spam score monitoring to flag any potential issues
Choose from different email sending schedules to reflect real usage
Works with a variety of inbox providers so probably compatible with the one your company uses
Clear email deliverability rate reports you know when your inbox is warmed up
Expensive to warm up multiple inboxes
Can be tricky to set up with Zoho according to Product Hunt reviewers
4. Mailwarm: An Expensive Alternative
Mailwarm is a straightforward and effective email warm up service. Mailwarm’s team has set up thousands of email accounts that your inbox will interact with on a schedule that you set. There’s no indication that the inboxes your emails will be sent to are real people’s inboxes, which could be a downside if ESPs look critically at your email activity.
Once you connect your email account, you can set your email warm up schedule, and Mailwarm will start sending and replying to emails for you, warming up your account over time.
If you start noticing too many Mailwarm emails taking up space in your inbox, you can create an inbox rule to store them all in a folder.
While they are an effective email warming software, their expensive pricing and lack of real user inboxes are the downsides to consider.
Who is it for: Anyone sending a cold email outreach campaign that wants to avoid the spam folder
Pricing: $828 per year, or $79 per month per inbox (billed monthly). $159 per month for up to three accounts. One of the most expensive email warming tools in this guide.
Engage with a network of Mailwarm’s own email addresses
Set your own sending and reply schedule
If you’re technical it’s easy to use, as it’s installed via a SMTP setup
Only works with SMTP setup, so it can be tricky to set up if you haven’t set inboxes up that way before
Users on Capterra struggle to integrate it properly with Gmail
Expensive option at $79 per inbox
5. WarmUpYourEmail: A Human Touch?
WarmUpYourEmail is a cold email inbox warming service that uses a real team to generate engagement with your emails.
Their team engages with your emails by opening them, replying to them, marking them as important, and removing them from the spam folder (if your emails land there).
It’s worth noting that there are no clear details on how their team manages to do this, and we’d recommend contacting WarmUpYourEmail if you have questions about the process.
Like most tools in this guide, WarmUpYourEmail is a paid service. They're in the mid-to-high pricing range, and similar to others, they also charge per inbox. It’s free for Mailshake users, if you use that for your cold emailing needs.
Who is it for: Anyone needing a simple inbox warm up service before sending bulk emails to cold prospects or in a marketing campaign
Pricing: $29/month per inbox, for 50 emails per day on one account. $49 per month for 50 emails per day on three email accounts.
Real people opening, replying, and engaging with your emails
Helpful free tools to review your DMARC, SPF, SMTP
Works with all major inbox providers
No information on how their email warm up service runs in the background
Becomes expensive if you want to send more than the base number of emails per day
6. lemwarm: Used To Be Popular
Lemlist were the first to come to market with an email warmup tool (lemwarm). They deserve recognition for that, which is why we included them here.
Lemwarm is a simple and straightforward 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, just like the other tools on our list.
Emails that your inbox sends and receives using lemwarm are automatically tagged by your Gmail or Outlook account, so you know you can ignore the emails and they won’t get in the way of other important team or client communication.
Lemwarm is positioned in the mid-to-high pricing range, like WarmUpYourEmail, and they also charge per inbox. It’s worth mentioning that Lemwarm is included in the standard Lemlist pricing plans too.
Who is it for: Anyone wanting to improve their email deliverability.
Pricing: $29/month per inbox.
Choose how many emails you send per day
Automatically increase the volume of emails sent
One of the first to market, so they know the importance of email warmup
Relies on templates with unnatural email copy which can still be suspicious to inbox providers
Mid-to-high price range and not included in the standard plan by default
Can have issues with reliability, and users report that Lemwarm sometimes pauses without warning.
7. Mailreach: Good for a small number of inboxes
Mailreach is an easy-to-use email warm up platform to help you improve your deliverability.
Once you’ve connected your inbox, Mailreach will run on a fully automated schedule.
It includes inbox deliverability reports, email blacklist, DNS checks, as well as a smart warming algorithm to adjust the process continuously to get the best results.
The main drawback is that it’s a standalone platform and isn’t connected to any outreach platform, like the MailFlow Auto Warmer is. You’ll end up paying for both an email warm up service and a cold outreach tool at the same time, rather than simply using one that does everything for you.
Who is it for: Anyone needing a standalone email warmup tool
Pricing: $25 per inbox month for between one and five inboxes. For more than that, pricing lowers to $19.50 per inbox per month.
Works with Gmail, Outlook, and other third-party inbox providers
Fully automated, so you only need to check back semi-regularly to verify it’s performing as expected
Easy-to-understand dashboard that lets you monitor email warm up performance
Reviews on Capterra say it’s hard to warm up multiple email inboxes at once
Not connected to an email outreach tool so you’ll need to subscribe to one separately
8. Folderly: AI-Based email warmup?
Folderly is an email deliverability and warm up service that includes email warm up software as part of its offering.
The tool is aimed at large companies and it comes with a variety of helpful deliverability features. For example, there’s a basic email warm up tool that gets any account ready for basic outreach, then, an upgraded version for teams expecting to run high volume outreach that includes email content analysis and more powerful tools to diagnose potential issues.
The main drawback is that Folderly is expensive. It starts at $49 per month (which would get you both the email warm up and outreach tools on QuickMail) and then jumps to $200 per month if you’re running cold outreach campaigns. There’s also not much information on whether the inboxes in the network are real, or fake users created by Folderly. All Folderly says is that the inboxes are ‘trusted senders’.
However, it’s more powerful and comes with extra features that most options here don’t include, so it’s still worth considering if your company has the budget for a warm up tool like this.
Who is it for: Large teams with a budget who want an effective and quick way to warm up email addresses
Pricing: Starts at $49 per month for the basic warmup plan. $200 per month for specific cold outreach warm up features. $129 per month for email deliverability tests. The most expensive solution in this guide.
Email content analysis that will suggest improvements to copy based on how well it expects emails to be delivered
Email deliverability audit to identify causes of poor deliverability
Users say that the documentation is difficult to understand and the tool takes a while to set up correctly
No email outreach features included, so you’ll need to use a separate tool like QuickMail
9. Warmy: If your focus is email marketing
Warmy is a tool for email deliverability that’s made for teams with multiple email marketing inboxes that need warming up.
The tool uses an AI-based algorithm to automate the process of sending, receiving, and replying to emails from your inboxes to signal positive engagement and you can track how warmed up your inboxes are in visual dashboards.
Warmy includes a tool like QuickMail’s deliverability report, where you can track how effectively your emails are inboxing with all of the major inbox providers, such as Outlook, Gmail, AOL, and Zoho Mail.
Who is it for: Teams running bulk marketing email campaigns that need to warm up their inboxes.
Pricing: $49 per month for one inbox and 100 emails per day. $129 per month for three inboxes and 300 emails per day.
AI-based sending tools to quickly warm up your inbox
Deliverability checker that compares performance across the major inbox providers
Good customer support if you have issues
Lack of pre-made warm up templates so you need to create them yourself
Expensive compared to other options in this guide
10. Mailivery: Too early to try?
Mailivery is an email warm up tool to help sales teams improve their email deliverability.
Once you add your cold email inbox, the tool will send warm up emails on a schedule that you set. The schedule lets you mimic natural, human-like email patterns and lets you skip nights or weekends, for example.
It integrates with all major inbox providers, and it’s quick to get up and running with.
The tool automatically categorizes your warm up emails, so if you’re using the inbox for other activities during the warm up period they won’t block up your inbox. You can also monitor deliverability with an analytics dashboard, and your sales team will know when their inboxes are ready to start using for their cold outreach.
Who is it for: Sales teams wanting a quick way to improve deliverability for their cold emails
Pricing: $35 per inbox per month, which includes 35 warm up emails per day. $65 per inbox per month for 65 warm up emails per day.
Works with Gmail, Outlook, and custom inbox providers
Uses a peer-to-peer network of real inboxes (similar to MailFlow's Auto Warmer) for the most natural warm up pattern
Expensive considering the number of warm up emails per day is relatively low on the most affordable pricing plan
Users on Capterra say that there are no notifications if there are deliverability issues which could be harming your inbox in the background
Some customers report that there can be downtime for periods of up to 7 days without being notified of it
11. Klenty: Liteweight Email Warm Up Add-On
Klenty is a sales engagement platform made for people running multichannel outreach, including cold email. The company released an email warmup tool as an optional add-on to help users improve their email deliverability.
The warmup service sends emails at random times to generate natural activity on your account and provides reports showing you how many of your mails are landing in the primary inbox or in other inbox folders.
Who is it for: Those looking for a simple email warm up platform
Pricing: From $240 per year per inbox being warmed up. It’s an additional cost on top of your standard Klenty account, which starts at $50 per user per month.
As well as an email warming service, there’s a spam checker and email template review tool to help improve your cold outreach process
Clear reports on where your emails are landing: primary inbox, promotions, or spam
Expensive option because email warming isn’t included in the main Klenty pricing plans
12. Reply: Expensive for Multiple Inboxes
Reply is a sales outreach platform that includes cold email tools to help you reach out to cold sales prospects. The company offers an extra email warm up tool for Google Workspace and Outlook to improve deliverability and help you land in the primary inbox.
Reply’s email warm up tool costs $29 per inbox per month. The main downside here is that it’s going to represent a large extra cost if you’re part of a large sales team, or run a lead generation agency with multiple client accounts that need warming up.
The system works as you would expect – they use a peer-to-peer network of inboxes that send emails between each other, and then automatically opens, replies to, and removes emails from the spam folder to generate positive signals on your account.
Who is it for: Enterprise sales teams using Reply that want to quickly improve their domain reputation and warm up their inboxes.
Pricing: $29 per inbox per month. Included on the Professional plan for $90 per user per month, but optional extra on the Starter plan at $60 per user per month
If you’re already using Reply, it makes sense to use the add-on to easily connect your inboxes
Clear reports to show you where your emails are landing during the warm-up process
Uses a network of real inboxes rather than generating their own fake inboxes so it will be more natural
Not included in Reply’s Starter plan, so you’ll need to pay extra to use the email warming features
Is an Email Warming Tool Essential for Cold Emailing?
The simple answer? Yes.
Spam emails make up almost half of all email traffic, so email service providers (ESPs) — like Gmail, Outlook, Yahoo, and Zoho — have all developed effective filters to protect their users from spam.
Email warm up tools generate activity on your email account to prove to ESPs that you’re a trustworthy sender.
Even if you’ve used an email account for months or years without a problem, it’s still worth using an email warming system to lower your risk of being sent to spam and improve your sender and email reputation.
Can You Warm Up Your Email Manually?
You can warm up your email manually, but it’s going to take time. You’ll need to be sending and replying to emails multiple times throughout the day, and to be on the safe side, you’ll still need to keep this up even after you’ve launched your first cold email campaign.
You’ll need to ensure the people you’re emailing are replying to you, and there’s real engagement in your email threads.
If you have patience and time, manually warming up your email address works, but considering the quality of automated inbox warming tools available, manual email warming won’t be the best use of your time.
When Can You Turn Off Your Email Warming Software?
Considering some of these are paid tools, you might be asking how long you’ll need to use your email warm up software.
The best course of action is to leave your email warmer running, even after you’ve started sending your email campaigns.
The ongoing positive engagement that these tools can generate will help signal to your prospect’s email service provider that you’re a legitimate email user and aren’t spamming people.
For example, once the MailFlow Auto Warmer is running, you won’t even notice it working in the background — despite that, it’ll be continuously improving and monitoring your deliverability so you can send your cold email campaigns with confidence, knowing that you won’t get caught in the spam filter.
Should You Use a Specific Email Warmup Template?
Warming up your email should reflect a natural process. The emails you send and receive in the warm up process should look like natural conversation threads that you’d have with a colleague, client, or friend.
MailFlow's Auto Warmer uses business language that you use on a daily basis already in the warmup templates.
Each warmup template your inbox will send is unique and even includes your recipient’s real name.
Other Factors That Can Affect Your Email Warm Up Strategy
1. The Longer You’ve Owned Your Email Address, The Better
If you buy a brand new domain from Google Domains or Namecheap and start using it to send emails, email service providers won’t trust you. You need to establish your domain reputation, so warming up a new email address is vital if you want your cold emails to land in your recipients’ primary inbox.
To build trust with the major email providers, you’ll need to grow your email activity over time.
Another shortcut to building trust with Google in particular is to pay for six months of your G Suite subscription in advance. We talk more about this strategy here, but the premise is simple: Google is less likely to restrict a customer that is willing to pay for the service.
2. The Quality of Your Email List Matters
No matter how long you warm up your email for, everything will come crashing down if you send 1,000 emails to people who aren’t interested in your product or services and don’t want to hear from you.
Worse, you might be sending emails to invalid email addresses and they’ll be instantly rejected.
To avoid this, first, spend time building your email list. Make sure every person you reach out to is highly relevant to what you’re offering.
Then, use email verification tools like Dropcontact and NeverBounce to verify the email addresses in your prospect list are valid. You’ll show email service providers that you’re not just spamming every email address you can find, but instead, are sending targeted, personalized emails that your recipients will want to read.
3. The Level of Personalization in Your Outreach Emails Affects Deliverability
Finally, one of the most important lessons: always personalize your email outreach.
Every email you send should have unique personalization, such as your prospect’s:
This is going to help you get more replies to your outbound email campaigns, as well as being a positive signal to email service providers. They’ll know you’re not copy-pasting your template and are sending real, high-quality emails with a unique message for each recipient.
In QuickMail, you can use Attributes to personalize your outreach, even at scale.
For example, you can quickly add any personalization you need based on what you know about your prospect.
When someone receives your personalized email, they’ll know you’ve spent time researching them and will be more willing to have a conversation with you.
Wrapping Up: What’s the Best Cold Email Warm Up Tool for You?
There are a variety of powerful cold email warm up tools out there.
If you want to get started with a powerful and cost-effective tool, use MailFlow's Auto Warmer. It’s free to use, and within 1-2 weeks your sender reputation will be clearly improving.
Leave it running in the background, even after you’ve started to send your campaigns, and you’ll be confident knowing that your emails are always going to be seen by your prospects.
However, it’s key to remember that these warm up tools won’t solve every problem for you. You still need to invest in creating a high-quality prospect list, writing personalized and unique emails, and having a value proposition that the people you’re reaching out to care about, and are willing to engage with you to learn more about.