Warming up your inbox should be an essential part of your outbound cold email campaigns. It can help improve your email deliverability and sender reputation, preventing your emails from being wrongly identified as spam. Sending too many emails from a cold email account is a surefire way to be blacklisted by spam filters, causing none of the emails to go into the recipient's primary inbox.

In addition, you will prevent the possibility of getting blocked by your email provider, especially when using a new email address.

You can warm up your new email accounts in two ways: manually and automatically. Manual warmup is well known for its ability to build trust in the eyes of email service providers. As a result, it can help you save a lot of money.

Automated email warm up services do this for you by methodically sending out emails.

Either way, the email warm-up process is one of the best practices in outbound sales. Cold email addresses lead to failed campaigns.

How Manual Warmup is Usually Done:

Manually warming up your email address can be done by:

  • Account authentication by way of Domain Keys Identified Mail (DKIM), Sender Policy Framework (SPF), and Domain-based Message, Authentication, Reporting & Conformance (DMARC).
  • Sending Manual Mails to Close Circle of People
  • Keeping Conversations Threads Alive and Responsive
  • Encouraging Subscriptions to Your Newsletters
  • Personalizing Your Emails for Better Engagement

All these tasks work towards increasing the reputation of your email address and warm up newer email addresses as a solid email deliverability solution. However, it's much more practical to use automated email warm-up tools that send warm-up emails automatically for you. They increase email engagement by exchanging warm up emails. Email automation saves a lot of manual labor, leaving sales reps to work on more demanding tasks.

Why You Should Use Email Warm Up Tools

Although manual warmup is a great way to ensure positive interactions and improve email deliverability, it has its limitations. The warm up process can be extremely time-consuming and requires a great deal of attention to detail and effort. This is why many businesses prefer to use automated email warmup tools for their campaigns. They offer the benefit of automation and help save time and effort.

The Best Email Warm-up Tools

Let's look into some of the best tools that are widely used in the industry. Most of them are free email warmup tools that also offer premium plans. They make sure every email you send gets delivered instead of being automatically marked as spam. Some of them are basic utilities that allow you to just warm up email domains. Some others can generate email copies to send, too.

Warmup Inbox

Warmup Inbox is a popular email warm up tool that is known for optimizing engagement rates, the sender’s reputation, and deliverability and decreasing bounce rates effectively. It is a highly recommended tool used by many businesses around the world.

It allows you to warm your domain gradually by sending a few mails at a time.


Warmbox is a well-known inbox warmup tool that is available for use with the most popular email service providers. However, keep in mind that it doesn’t offer a free trial to interested users.

Warmbox works on the basis of artificial intelligence and GPT-3 technology and is known for its efficiency. It can prevent email providers from blacklisting your domain through its useful blacklist checker.

Warmbox is easy to use and doesn’t require any technical knowledge or skills. It comes with a simple plug-and-play setup. It works realistically and places a strong emphasis on generating positive interactions. It is preferred for its detailed analytics for the purpose of monitoring as well.

Warmbox offers different warmup options to choose from. It has a vast library of visually attractive email templates that can help increase trustworthiness. It is available as a free plan, but there are no theme options or inbox warmups available in it. It provides four pricing plans, namely, solo, start-up, growth, and team.


GMass is a freely available tool that is created and designed to be suitable for use only for Google or Google Workplace. However, it is perfectly safe for use and is widely used by businesses for their cold email and mass email campaigns. In addition, most Gmail users rely on it to build trust for their Gmail accounts.

Google’s limit for Gmail accounts is 500 emails per day, whereas it is 2000 per day for Google Workspace. GMass comes with an impressive capability where it begins with two emails per day and soon progresses to 200 warmup emails per day while ensuring a high rate of deliverability. After the 200 mark is reached, GMass will maintain the amount for as long as you need it to.

GMass is preferable to other email warmup tools for its understanding of Gmail and automated warmup system for speed and convenience. It allows you to set up the tool in a matter of minutes with its one-click feature. In addition, it has a smart auto-detection feature that performs a careful analysis of your Gmail account and understands the requirements accurately.

GMass also provides an auto inbox decluttering feature for the purpose of quickly archiving warmup emails that you receive. In addition, you can set the ideal starting frequency in the GMass dashboard with ease. GMass is also available as a Google Chrome extension.

It is easy to switch from an email warmup tool that you’ve been paying for to GMass. It will help ensure that your performance doesn’t get affected, and you will have a firm understanding of your sending patterns.

QuickMail Auto Warmer

QuickMail Auto Warmer is a great tool that is available for free for the first 50 inboxes. It can help you save the trouble of changing domains. The auto warmer can help maintain your campaign performance and help resolve the issue of poor sender reputation in a short period.

It provides auto reply and auto archive features to save time. It is suitable for businesses as it uses professional business language in automated engagement mails. It is available as a Starter and Pro plan.

QuickMail Auto Warmer provides detailed deliverability reports to identify areas of improvement, prevent the domain from getting blacklisted and optimize your email deliverability successfully.

However, keep in mind that Auto Warmer deliberately chooses to have a sending limit on the number of warmup emails that can be sent per day. This is done to ensure and maintain the quality of the inboxes. In addition, it provides premium customer support for the quick resolution of different queries and issues.


Folderly is an easy-to-use platform designed to help businesses optimize their email deliverability. It relies on artificial intelligence to help businesses meet their objectives through the email service provider of their choice. The AI used by Folderly is known for its sophistication in mimicking human interactions and avoiding the possibility of spam.

It is a highly responsive platform that comes with an easy-to-use spam checker tool. It provides scope for deliverability tests and email deliverability audits as well. It has a dedicated email deliverability team of experts available to address and resolve any issues that may arise in the use of the platform.

Folderly provides businesses with the scope to run domain health checkups in a short period. In addition, it provides an accurate deliverability score for free. It also performs active IP monitoring and provides scope to businesses for the analysis of inbox placement.

It comes with email authentication and DNS settings as well. It offers plenty of useful information and resources in its ‘Email Academy’ to help users get started. It is available in three pricing plans, namely, basic warmup, cold email outreach, and email marketing. It is known for its high-quality consultation in the area of email marketing.


This is a tool made available by OutReachBin, which is designed specifically for the purpose of email warmup. It relies on a peer-to-peer network for its service and is known for its interactions with real businesses. It is available for use with most of the top-rated email service providers. Unfortunately, it offers no free trial for interested users.

InboxWarm places a strong emphasis on ensuring and maintaining human-like email activity. It is more accurately described as an advanced multi-layer algorithm for email warmup activation. InboxWarm performs automatic interactions with emails and ensures a high level of positive interactions to prevent your emails from ending up in the spam folder.

Lemwarm by Lemlist

Lemwarm by Lemlist is a top-rated tool for email warmup and deliverability. Its objective is to provide businesses with a consistent level of engagement. It works mainly by sending highly personalized emails in small numbers and increasing the sender’s reputation on a steady basis. It is recognized for its high degree of reliability and aversion to using fake accounts.

Lemwarm is available for use in over 100 countries, and it has a huge community of users. Hence, because it works with real people, you can expect to receive high open rates. It has a well-developed mailbox network with many popular companies.

Lemwarm takes a unique approach or strategy to the process of email warmup. It has a sophisticated algorithm that relies on a huge number of parameters to ensure success.

In addition, it generates unique subject lines and replies to messages with unique content. Hence, you can expect to maintain conversations under the same threads consistently, which gives it a clean look of a conversation.

Warm Up Your Email by Mailshake

This useful Mailshake tool stands out from the other tools because of its unique capability to generate engagement for emails. In addition, it provides scope for easy review through its free-to-use tools like Spam Checker Beta, SPF Checker Beta, DMARC Checker Beta, and SMTP Checker Beta.

It is recognized for its sophisticated pattern monitoring and spam scoring system to help you find out how many of your emails end up in people's spam folders. In addition, it is available in three pricing plans, namely, sole sender, pro sender, and agency sender.

It provides a space for the easy measurement of cold emails that come into the inbox. In addition, Mailshake has an active team of passionate experts who quickly open your emails and reply to them. All you need to do is connect your email ID with Mailshake in order to initiate the warming-up process.


Reply is a peer-to-peer tool known for its high-quality and efficient automation service. It is popular for its ability to optimize the process of inbox placement. Many businesses that have suffered low sender reputation have found Reply’s service useful in repairing and boosting their sender reputation within a span of a few weeks or months.

It is available as a demo. Reply operates on the basis of the Pay-as-You-Go pricing model, where the emphasis will be on your pattern of usage. The paid plans can be canceled anytime without any restrictions holding you back.

You can have several warmup profiles to meet the complex requirements and objectives of your business. You can check the validity of your DNS settings and records associated with DNS with great ease. You will also receive informative reports about the number of emails sent and spammed. 

It offers a GPT-3 assistant for auto-generated texts and offers several templates as well. It is known for its ability to bring order to the emails in the inbox for convenience. Reply has a well-developed Knowledge Base comprising a Help Center, Sales Tools Catalog, Reply Academy, Outbound Sales Score, Subject Line Generator, and API.


Woodpecker is a warmup and recovery system that can get to work with a single click. You have the option of using it for your email address or even the entire domain. It is known for its efficacy in helping businesses get the ideal warmup scenarios more frequently. It comes with no extra costs and has deliverability experts committed to ensuring that the users receive the best possible outcome consistently.

Woodpecker performs spam checks and bounce shields. It also provides randomized sending frequency and works on the basis of advanced sending parameters. It also performs an audit of the domain to help you stay updated.

It also provides advanced campaign automation that comes with features like A/B testing, autoreply detection, and in-thread follow-ups, among others. In addition, it is available for integration with Google Sheets, Pipedrive, HubSpot, Calendly, and Zapier.

Woodpecker also provides scope for sales automation and lead generation for clients. It comes with the capability of meeting a wide variety of outreach needs. It is suitable for use by businesses of different sizes and scales of operations. It also comes with supporting products like Woodpecker Calls and Signature Generator. It offers a vast amount of resources in the form of blogs, guides, ebooks, glossaries, and Academies.


Mailreach is known for its capability of realistically engaging emails through automation. It focuses on optimizing the open rates, click replies, and lead rates. It ensures that no random content is shared with your target audience and provides high-quality content that feels natural and engaging. The best part about using Mailreach is that you get a complete picture of how your reputation has grown with time.

Mailreach is used by businesses of different types and sizes around the world. It is available for use with Gmail, Office365, SendGrid, Custom STMP, and MailGun, among others.

It offers IP warming service and Email warmup API as well. It is equipped with a smart and complex warming algorithm that can manage different parameters effectively. You also receive high-quality support and assistance, which will be available around the clock. It has an active blog available as well.

To Sum Up

Email warmup tools have proven to be indispensable to the cold email community. Before you select an email warmup tool for your business, make sure to compare the prices of the different tools and have a proper understanding of the various pros and cons that come with the use of each email warmup tool. Some email warmup tools are guilty of providing gibberish content. Hence, it is important to check for quality.

As you remain consistent in your email warmup efforts, whether through manual or automatic means, you will find your business growing in size and your campaign needs becoming more complex. It is an essential part of email strategy. At the end of the day, it's not just the sender reputation and email deliverability that matters. The actual content matters too.

A major downside to using email warmup tools is that they can be expensive in the long run, especially if you are growing at a fast pace. Free tools usually have their limitations. Hence, it is important to select the right email warmup tool that will be able to accommodate your requirements as your business grows in size.