Most email warmup tools focus on improving the reputation of your sending domains, but there is an additional step you can take to level up your deliverability even further. By testing your campaign messaging, you can ensure there’s nothing in your content that’s likely to trigger spam filters and affect your deliverability. With a trusted domain and trustworthy content, you have everything you need to land in the primary inbox.

This article explores three leading email warmup tools, detailing their features and pricing to help you choose the best fit for your needs.

What Is Email Warmup?

Email warmup is the process of gradually building a good reputation for a new or inactive email account. ESPs are naturally suspicious of new accounts that immediately start sending high volumes of emails, because it’s a common tactic spammers and scammers use.

To determine if an account is trustworthy, ESPs monitor several key signals:

• The age and sending history of the domain.
• The volume and frequency of sent emails.
• Engagement rates, such as opens and replies.
• The number of times emails are marked as spam by recipients.

Email warmup tools solve this problem by simulating natural, human-like email conversations. They connect your account to a vast network of other inboxes and automate a steady exchange of emails. Starting with a low volume of messages, they gradually increase the number over time. They also generate opens, replies, and even mark your emails as “not spam” if they land incorrectly. This activity signals to ESPs that your account is legitimate, building the positive sending history required for high-volume campaigns.

In addition to basic warmup, some tools will also check the content of the campaign’s emails you intend to send, giving you an extra layer of protection and preparation.

Top 3 Email Warmup Tools

Here are three of the most powerful tools for automating the email warmup process.

1. Instantly

Instantly is an all-in-one cold outreach platform with a powerful email warmup tool. It is designed not only to prepare your email accounts for sending but also to manage entire campaigns from a single dashboard. The platform’s main draw is its unlimited email account and warmup feature, allowing you to scale your outreach efforts without incurring extra costs for each new inbox.

The service works by sending and receiving emails through its network of users, creating positive interactions that build your sender reputation. Instantly provides a clear deliverability score, so you can monitor which emails are landing in the inbox versus spam and know precisely when an account is ready for outreach.

Key features include:

• Unlimited email warmup: Connect and warm up as many email accounts as you need under a single plan.
• Automated engagement: The system automatically sends, opens, and replies to emails to build a positive sending history.
• Deliverability testing: A built-in tester shows you where your emails are landing across major providers like Gmail and Outlook.
• All-in-one platform: Combines warmup with campaign management, lead sourcing, and analytics.

Pricing: Instantly’s plans start at $30 per month, which includes unlimited email accounts and warmup capabilities, along with a sending limit of 5,000 emails per month. Higher-tier plans increase the sending volume and add more advanced features.

2. Mails.ai

Mails.ai offers a suite of tools for cold emailing, with a free and effective email warmup service at its core. It uses an AI-driven algorithm and a network of real, safe inboxes to improve your sender reputation and deliverability. The platform is designed to be straightforward, allowing you to connect your inbox and start the warmup process in minutes.

The warmup process at Mails.ai focuses on creating realistic, human-like email exchanges. It also has a campaign warmup feature that tests your email templates to see if they’re considered safe by various ESPs.

Key features include:

• Free warmup tool: Provides a robust email warmup service at no cost.
• AI-powered conversations: Utilizes AI to generate unique and natural-sounding email content for interactions.
• Reputation monitoring: Offers reports to track your deliverability and see how your sender score improves over time.
• Spam score checker: Helps you analyze your email copy to identify and remove words that might trigger spam filters.

Pricing: The email warmup feature is free. Paid plans, which include an AI writer and lead generation tools, start at $24 per month.

3. Warmup Inbox

Warmup Inbox is a specialized tool focused exclusively on improving your email sending reputation. It connects your inbox to its peer-to-peer network of over 4,500 real inboxes. The platform automates the process of sending and receiving emails, ensuring your account engages in positive interactions daily.

The service provides detailed reporting on your warmup progress, including a health score for your inbox, deliverability rates, and a breakdown of where your emails are landing. This allows you to see tangible proof of your improving reputation. Warmup Inbox is compatible with all major email providers, including Gmail, Outlook, and custom SMTP servers, making it a versatile choice for any business.

Key features include:

• Large P2P network: Leverages a network of thousands of real inboxes to generate authentic engagement.
• Detailed health score: Provides a comprehensive dashboard to monitor your inbox reputation and deliverability metrics.
• Automated spam recovery: If a warmup email lands in spam, the tool automatically marks it as “not spam” to repair your reputation.
• Broad provider support: Works seamlessly with virtually any email service provider.

Pricing: Plans are based on the number of email accounts you need to warm up. The entry-level plan costs $12 per month for one inbox. A plan for five inboxes is available for $49 per month, with larger packages available for agencies and teams.

Final Thoughts

Investing in an email warmup tool is a proactive step toward ensuring the success of your email marketing efforts. By systematically building a positive sender reputation, you can significantly increase the chances of your messages landing in the primary inbox, where they are most likely to be seen and engaged with.

The best tool for you will depend on your specific needs. However, as an all-in-one solution that combines warmup with campaign management, we think Instantly offers incredible value, which is why it’s at the top of this list.