Are domain warmup tools like Lemwarm or WarmupInbox effective and safe to use?

Summary

Domain warmup tools like Lemwarm and WarmupInbox aim to improve email deliverability by simulating engagement and building sender reputation. While some users report ease of use and deliverability improvements, others warn that mailbox providers may detect such practices as inauthentic, leading to negative consequences. Experts emphasize that the warm-up process is an introductory step, not a permanent solution, and must be supported by a robust email program with good data acquisition, content targeting, and consistent sending practices. Essential technical aspects include email authentication (SPF, DKIM, DMARC), using seedlists, monitoring deliverability metrics, and gradual increases in sending volume. Key recommendations include focusing on quality content, clean email lists, proper email authentication, and avoiding automation that simulates engagement.

Key findings

  • Mixed Opinions: Experiences with domain warmup tools vary; some find them effective, while others see limited or negative impact.
  • Authenticity Concerns: Mailbox providers may penalize simulated engagement, affecting domain reputation.
  • Gradual Warmup is Key: Slowly increasing email volume and frequency is crucial to establishing a positive sending reputation.
  • Authentication is Essential: Proper setup of SPF, DKIM, and DMARC is necessary for legitimate email programs and preventing abuse.
  • Data and Content Quality: High-quality content and clean data are vital and tools will not solve those problems.

Key considerations

  • Address Root Causes: Identify and fix underlying deliverability issues (data, content, targeting).
  • Comprehensive Strategy: Domain warming should be part of a holistic deliverability strategy, not a standalone fix.
  • Prioritize Genuine Engagement: Focus on creating engaging content and building genuine relationships with subscribers.
  • Monitor and Adjust: Continuously monitor deliverability metrics and adapt strategies based on performance.
  • Long Term is Important: Ensure the senders reputation will work well beyond the tool.

What email marketers say
11Marketer opinions

Domain warmup tools like Lemwarm and WarmupInbox aim to improve email deliverability by simulating engagement and building sender reputation. While some users report ease of use and deliverability improvements, others warn that mailbox providers may detect such practices as inauthentic, leading to negative consequences. Experts emphasize the importance of addressing underlying deliverability issues such as poor data acquisition and content targeting, rather than relying solely on warmup tools. Effective IP/domain warming also involves gradual increases in sending volume and proper email authentication setup.

Key opinions

  • Mixed effectiveness: Some users find domain warmup tools effective for improving deliverability and maintaining sender reputation, while others see them as providing only a temporary boost.
  • Potential risks: Mailbox providers may detect and penalize simulated engagement, resulting in a negative impact on domain reputation.
  • Importance of good practices: Focusing on quality content, clean email lists, and proper email authentication (SPF, DKIM, DMARC) is crucial for long-term deliverability.
  • Gradual warming: Warming up involves gradually increasing sending volume over time to establish a positive sending reputation.

Key considerations

  • Root cause analysis: Identify and address the underlying causes of deliverability issues, such as poor data quality or unengaging content.
  • Long-term strategy: Domain warming should be part of a broader deliverability strategy that includes best practices for email marketing.
  • Authenticity: Prioritize genuine engagement over artificial methods to avoid penalties from mailbox providers.
  • Monitoring: Continuously monitor deliverability metrics and adjust strategies as needed.
Marketer view

Email marketer from Email Geeks shares that if you use a service like this we will a) most likely spot the gaming going on and shut it down and b) your domain reputation will take a major hit. So chances are you will achieve quite the opposite of what you were trying to achieve …

April 2021 - Email Geeks
Marketer view

Email marketer from Email Geeks shares that domain warming tools are sketchy, and mailbox providers will eventually catch up to anything you are trying to fake - be it spoofed email headers or be it fake engagement. They believe the only way it could work is a very temporary boost in reputation.

January 2024 - Email Geeks
Marketer view

Email marketer from Quora answers that while domain warming can help build initial sender reputation, it's essential to focus on sending valuable content and maintaining clean email lists. Domain warming alone won't solve deliverability issues if your content isn't engaging or your list is outdated.

May 2021 - Quora
Marketer view

Email marketer from Reddit shares that domain warming is more important than ever to get a cold email strategy going. A good domain warmup strategy and tool is essential.

September 2022 - Reddit
Marketer view

Email marketer from Mailjet answers that warming up a new domain or IP address is important to demonstrate legitimacy to mailbox providers. This involves gradually increasing sending volume, monitoring deliverability, and maintaining good sending practices.

June 2024 - Mailjet
Marketer view

Email marketer from Klenty shares that warming up your IP address ensures that your emails land into the inboxes and not spam folders. To establish your email address as legitimate, IP Warming is crucial.

August 2021 - Klenty
Marketer view

Email marketer from G2 shares that Lemwarm is easy to use and improves deliverability. It helps keep sender reputation high, preventing emails from landing in spam folders. It allows for a 'set it and forget it' approach to email warming.

November 2023 - G2
Marketer view

Email marketer from Hunter.io shares that an email warmup process gradually builds your positive reputation as a sender by starting with sending a few emails a day and slowly scaling up as your reputation strengthens.

January 2025 - Hunter.io
Marketer view

Email marketer from Email Geeks advises against using domain warming tools and suggests finding out why the client believes they need it. They state that domain warming services work in different ways but generally attempt to fake legitimate traffic/engagement for domains that can't generate that organically. They added that they use a mesh of their spamming (cold outreach) service users to create the fake engagement.

March 2024 - Email Geeks
Marketer view

Email marketer from Woodpecker.co answers that Lemwarm is one of the methods of warming your email up which is useful when setting up a new domain and email account, or increasing sending volume. They also say it can repair a bad sender reputation.

October 2022 - Woodpecker.co
Marketer view

Email marketer from Reddit states that domain warming services can provide a temporary boost to reputation, but it's crucial to address the underlying issues causing deliverability problems. Faking engagement is a short-term solution and not sustainable in the long run.

December 2023 - Reddit

What the experts say
3Expert opinions

Experts highlight that domain and IP warming is about establishing initial recognition with email systems, not creating a permanent reputation. Warming up practices must be coupled with good overall email practices. Essential aspects include email authentication (SPF, DKIM, DMARC) and monitoring deliverability through seedlists.

Key opinions

  • Introductory Process: Domain warm-up introduces you to email systems, but doesn't create a lasting reputation.
  • Email Authentication: Proper setup of SPF, DKIM, and DMARC is crucial alongside IP warming.
  • Monitoring Deliverability: Using seedlists and tracking deliverability metrics is important during IP/Domain warming.

Key considerations

  • Sustainable Reputation: Ensure your own email stream is strong enough to maintain reputation after the warm-up period.
  • Abuse Prevention: Email authentication helps prevent abuse and demonstrates legitimate email practices.
  • ESP Considerations: Pay close attention to warming strategies when using a new or unknown Email Service Provider.
Expert view

Expert from Email Geeks explains that domain warm up is about introducing yourself to a system. It’s not “do this to develop a reputation and that reputation is now permanent”. If your own mail stream isn’t good enough to create a reputation then when you stop using the warmup system your own reputation needs to develop.

December 2024 - Email Geeks
Expert view

Expert from Spam Resource shares that using seedlists and tracking your deliverability metrics with them is an important step in IP/Domain warming up, especially if you are using a new or unknown Email Service Provider.

August 2021 - Spam Resource
Expert view

Expert from Word to the Wise explains the importance of email authentication and how it contributes to sender reputation, especially during IP warming. It emphasizes that proper setup of SPF, DKIM, and DMARC is crucial for legitimate email programs and helps prevent abuse. They emphasize good email practices alongside warming.

September 2021 - Word to the Wise

What the documentation says
4Technical articles

Email providers like Google, Microsoft, SparkPost, and Sendgrid emphasize the importance of gradually warming up new IP addresses to establish a positive sending reputation. This involves slowly increasing email volume and prioritizing the sending of legitimate, valuable emails that recipients want. They advise against using automated tools to simulate engagement, as this can damage sender reputation.

Key findings

  • Gradual Warm-up: Slowly increasing email volume is crucial for establishing a positive sending reputation.
  • Valuable Content: Sending legitimate, valuable emails that recipients want is essential for building a good sender reputation.
  • Avoid Automation: Automated tools that simulate engagement can damage sender reputation.

Key considerations

  • Deliverability Monitoring: Continuously monitor deliverability rates during the warm-up process.
  • Engagement Metrics: Base volume increases on engagement and deliverability metrics.
  • Legitimate Sending Practices: Prioritize sending genuine emails that recipients find valuable.
Technical article

Documentation from Google explains that warming up a new IP address gradually is important to establish a positive sending reputation with Gmail. This involves slowly increasing the volume of emails sent over time and monitoring deliverability rates.

April 2022 - Google Workspace Admin Help
Technical article

Documentation from Microsoft states that building a good sender reputation requires consistently sending legitimate, valuable emails that recipients want to receive. They advise against using automated tools to simulate engagement, as this can damage sender reputation.

January 2022 - Microsoft
Technical article

Documentation from Sendgrid shares that creating a sending reputation is important. It involves consistently sending legitimate email that recipients want. They advise following their documentation on how to warm your IP up.

January 2023 - Sendgrid
Technical article

Documentation from SparkPost explains that gradually increasing sending volume over time is key to establishing a healthy IP reputation. They recommend starting with small volumes and slowly increasing them based on engagement and deliverability metrics.

May 2024 - SparkPost