Note: As of late January 2023, Gmail is making a push to end email warmup services. See this blog post for more details. Outlook email warmup services are not yet known to be affected, however.
Are your cold emails going to spam, or your recipients’ inboxes? That may depend on whether your cold emails are being sent by an email address that’s “warm” enough.
That’s why email warmup tools and email warmup services exist – to take the “cold” out of cold emailing and increase delivery rates for your messages.
But how exactly does email warmup work? And what are the best email warmup tools?
Table of Contents
- What Is an Email Warmup Service?
- Why Is Email Warmup Important?
- The 10 Best Email Warmup Tools
- 1. Warm Up Your Email ($29/mo per inbox) – The highest quality, mid-price option
- 2. Mailflow.io Auto Warmer (Free) – A mid-quality, free option
- 3. Smartlead.ai ($39/mo for unlimited inboxes) – A mid-high quality, low price option
- 4. Saleshandy ($34/mo for unlimited inboxes) – A mid quality, low price option
- 5. WarmUp Inbox ($12/mo per inbox) – A mid quality, low price option
- 6. Lemwarm ($29/mo per inbox) – A high quality, mid-price option
- 7. Instantly.ai ($37/mo for unlimited inboxes) – A mid quality, low price option
- 8. Folderly ($49/mo per inbox) – A high quality, high-priced option
- 9. Mailwarm ($69/mo per inbox) – The high quality, highest-priced option
- 10. Warmbox ($15/mo per inbox) – A mid quality, mid price option
- 11. InboxWarm ($20/mo per inbox) – A mid quality, mid price option
- FAQs About Email Warmup
- The Bottom Line
What Is an Email Warmup Service?
An email warmup service is a platform that allows you to establish and grow the trust of your email accounts that you use for cold emailing.
Here’s how it works.
Ordinarily, when you send a cold email to a prospect you’ve never reached before, your ESP will review your domain, your sending history, and your message itself. If the ESP notices anything spammy or strange, it sends your message to your recipient’s spam folder. Obviously, that means they’re not gonna read it.
This effect is especially dangerous for newcomers to the cold email world. If you send too many emails too quickly from a new domain, you could end up with all your messages in spam folders.
Email warmup services send and receive automatic emails with other email addresses in the network to effectively simulate legitimate conversations – and “trick” ESPs into thinking you’re just sending and receiving normal, everyday emails from your cold email accounts.
After enough time and repetition, you’ll build trust with your ESP. You can gradually increase the number of emails you send out, broaden your targeting, and start scaling up your quantity of sends.
In short, gives you a shortcut to establishing trust with your ESP so you can send emails that land in the inboxes of your recipients rather than spam folders.
Depending on the warmup email service you use, the initial process typically takes 3 to 4 weeks. After that, you can continue email warmup practices to minimize your likelihood of getting sent to spam folders while ramping up your actual cold emails to win sales.
Why Is Email Warmup Important?
If you’re planning on executing a cold email strategy as part of your sales or marketing campaign, email warm up is a practical necessity. That’s because if you start blasting out thousands of emails from an address that doesn’t have a strong reputation, most of your messages are going to end up in a spam folder.
The Benefits of Email Warmup
These are some of the top benefits of pursuing an email warm up strategy:
- Get in the inbox, not the spam folder. Your emails are only effective if they end up in the inboxes of your recipients. Brands that practice email warmup see superior inbox placement, allowing them to effectively reach more people.
- Higher open rates. In line with this, brands that use email warmup tools see higher open rates. You’ll reach your audience more consistently, so assuming your messaging is relevant and your subject lines are on point, you should see higher open rates.
- Better response rates. Your response rates are certainly going to improve if your emails are hitting inboxes instead of spam folders!
- A better reputation across ESPs. Improving your domain’s reputation with an ESP can have a broader effect. You can enjoy a better reputation across many different ESPs and continue expanding your cold email strategy.
The 10 Best Email Warmup Tools
The best email warmup tools make it easy to follow a warm up email strategy – and these are some of the best tools available in 2022:
1. Warm Up Your Email ($29/mo per inbox) – The highest quality, mid-price option
Warm Up Your Email is the only tool on the list that doesn’t use automatically generated nonsensical email copy. They actually employ a team of human emailers to generate real human-written emails.
They’ll use automation to automatically send emails from your email accounts to their network of inboxes, which they then reply to manually. If your emails land in spam folders, they’ll remove them from the spam folders, which can help to repair a damaged ESP reputation.
You’ll also get analytics on your cold emails so you can see how many are landing in spam or inbox folders for each ESP.Pricing starts at $29/mo per inbox, but the service is provided for free to Mailshake users. Mailshake is one of our highest-rated cold email outreach tools, so the two tools go hand-in-hand.
2. Mailflow.io Auto Warmer (Free) – A mid-quality, free option
Auto Warmer, from QuickMail, is what this used to be. But after Gmail pulled the plug on auto warmup services, this service was transferred over to Mailflow.io. It’s free and compatible with Gmail and Outlook inboxes. You do have to start the free trial (which requires a credit card) to get access to the Auto Warmer, but it’s free to use after that, even after the free trial expires.
It offers a clean, easy interface to set up your email accounts on the warmup service, and takes care of it all automatically for you. I also like how it requires that you request access to the network, which then must be approved before you can join the warmup network. It adds a layer of security and quality to the network.
Can’t ask for much more from a free service!
3. Smartlead.ai ($39/mo for unlimited inboxes) – A mid-high quality, low price option
Smartlead is a newer platform that offers clean aesthetics and excellent pricing. Warmup emails are sent using OpenAI integration, so the email copy isn’t just gibberish like some of the other options farther down this list.
4. Saleshandy ($34/mo for unlimited inboxes) – A mid quality, low price option
With Saleshandy, you can warm up multiple email domains at the same time. The emails you send via this email warmup tool are sent to legitimate email addresses, which then read, reply to, and mark important your messages. Setup is automated, daily reports are generated consistently, and you can track your progress with a predicted email deliverability percentage and an email health score.
You can also keep an eye on your email/domain age. The starter package is $7 per month (billed annually), but you can get access to more advanced features at $25 per month.
5. WarmUp Inbox ($12/mo per inbox) – A mid quality, low price option
It’s compatible with Outlook and Gmail, and it’s a simple set-it-and-forget-it setup.
Basic plans start at $12/mo per inbox.
6. Lemwarm ($29/mo per inbox) – A high quality, mid-price option
Lemlist’s tool Lemwarm was the original email warmup service. It was so successful, that it spawned all the other tools on this list as competitors. Joining Lemwarm puts you into its network with other Lemwarm users, where its automation algorithm then sends automatically generated emails to and from other emails in the network. One fun benefit of Lemwarm is the hilarious auto-generated email copy it uses. Here are a few examples of subject lines from my testing:
“Draped neatly on a hanger, a banana is a cow from the right perspective.”
“In recent years, the currants could be said to resemble agreeable snakes.”
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“The literature would have us believe that a nice bear is not but a cat.”
I stopped using Lemwarm because of the price, but I do miss the silly subject lines it generates!
Unfortunately, there’s no free version of this tool – you’ll need to pony up $29 per month to use it.
7. Instantly.ai ($37/mo for unlimited inboxes) – A mid quality, low price option
Instantly sports an intuitive, clean UI and makes it easy to get started. Pricing is simple and includes unlimited inboxes, which is a major plus.
8. Folderly ($49/mo per inbox) – A high quality, high-priced option
Folderly is an AI-based platform that creates genuine-looking human conversations between its many email addresses.
Though this tool is more expensive than most others on this list, it also integrates with most ESPs (including Gmail and Outlook) and offers a suite of tools to support your email warmup strategy. Plans start at $49 per month.
9. Mailwarm ($69/mo per inbox) – The high quality, highest-priced option
Mailwarm is another high-priced option that focuses on quality engagements. Your emails will be moved out of the spam folder, opened, marked as important, and replied to by other inboxes in the network. They also provide analytics and reporting.
It’s a high-priced option at $69/mo per inbox, and frankly I don’t see the need to pay so much for a service, but it’s an option if you’ve got the budget!
10. Warmbox ($15/mo per inbox) – A mid quality, mid price option
Warmbox uses an AI algorithm to send and receive emails between 35,000+ different inboxes in the network. It’s compatible with most ESPs, including Gmail and Outlook, offers detailed reports, and comes with a domain blacklist and DNS deliverability checker.
For 1 account and 50 emails per day, you’ll pay $15 per month, with more advanced, more expensive plans available. Currently, no free trial is available.
11. InboxWarm ($20/mo per inbox) – A mid quality, mid price option
Offered by OutreachBin, InboxWarm is similar to many of the other tools on this list.
No free trial is currently available, and pricing start at $20/mo per inbox – but this also gives you access to a suite of cold email service tools.
FAQs About Email Warmup
Are you unsure about where to begin with an email warmup strategy?
These frequently asked questions (and answers) should help clarify some things:
Do I really need to do email warmup?
It’s possible to start a cold email outreach campaign without an email warmup strategy. But it’s usually a bad idea.
If you have a new domain, or if you rapidly scale up your sent emails, you’re probably going to get most of your messages flagged as spam. This will cripple your cold email outreach strategy and render your emails incapable of reaching your target audience. Email warmup isn’t fun, but it’s a practical necessity for most salespeople and marketers.
Can’t I just warm up email inboxes manually?
Yes, but it’d be incredibly inefficient. Technically, you can use your new domain to send out emails to any email inboxes you can control; you can move your emails out of spam folders, mark them as important, and even generate your own manual responses.
Do this enough, and you can build your own reputation manually. The problem is, this is painfully time consuming; you can get much better results and get them much faster by just using one of the tools in this list.
When should I start email warm up?
Ideally, you should start warming up your email inbox as soon as possible. For 3-8 weeks before sending out your first cold email, you should be warming up your email account. The sooner you start, the sooner your cold emails will be protected from spam folders.
How long does it take to warm up an email address?
Your reputation growth depends on many different variables, but generally you’ll see good results after 3 to 4 weeks of consistent email warmup.
Does email warmup guarantee better email deliverability?
Email warmup services are highly reliable for improving email deliverability, but nothing in the world of email sales or marketing is perfect. You’ll need to carefully monitor and review your reputation to make sure it’s improving as intended.
Do I need to keep warming up my email inbox forever?
Yeah, I recommend it. Unless your cold emails are generating tons of opens, replies, and engagement on their own, it can’t hurt to have an email warmup service do those things for you while your cold email campaign is running.
It’ll help shield your email address’s reputation to keep emails out of spam folders in the long run.
The Bottom Line
The bottom line here is that email warm up tools and services are a practical necessity if you want your sender reputation to be high enough to make your cold email strategy effective.
By using authentic responses and engagements, email warmup tools can boost your sender reputation over time, eventually allowing you to reach more inboxes and avoid spam folders. From there, it’s a simple matter of crafting persuasive messaging and interesting subject lines so you can adequately capture your target audience’s attention.
So after you’ve chosen a cold email outreach tool, what’s the next step?
EmailAnalytics lets you measure and improve the email response time of all your reps. What’s the point of running a cold email outreach strategy if you’re losing sales from poor performance?
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Jayson is a long-time columnist for Forbes, Entrepreneur, BusinessInsider, Inc.com, and various other major media publications, where he has authored over 1,000 articles since 2012, covering technology, marketing, and entrepreneurship. He keynoted the 2013 MarketingProfs University, and won the “Entrepreneur Blogger of the Year” award in 2015 from the Oxford Center for Entrepreneurs. In 2010, he founded a marketing agency that appeared on the Inc. 5000 before selling it in January of 2019, and he is now the CEO of EmailAnalytics.