How to Warm Up Email Domain – Ultimate Guide for Improved Deliverability in 2023

How to warm up email domain: what is it? 

Starting to send emails from a new domain? The question that’s probably on your mind is “how to warm up email domain”. Warming up your email domain isn’t just important, it’s like the secret sauce to making sure your emails actually get read and not tossed into the spam bin.

So, what’s this warm-up thing all about? It’s like stretching before a big run. You start slow, sending just a few emails, and then you gradually pick up the pace to warm up your IP. This way, those Internet Service Providers (ISPs) don’t get spooked and think you’re just another spammer.

Now, we can’t stress this enough: warming up your email domain is super important whether you’re sending a marketing email or cold emails. It’s the difference between your emails being welcomed with open arms or getting the cold shoulder.

If you do it right, you’re building a bridge of trust with ISPs, and that’s a big deal. You need to lay down the groundwork so that your email campaigns can strut their stuff right into inboxes, where they belong. In this guide, we’ll walk through how to warm up email domain automatically using an automated email warm up tool and how to warm up email domain manually. 

Why should you warm up email domain? 

There are several scenarios where you might find it necessary to warm up your email domain:

  • Switching to a new email service provider (ESP):

    When you move to a new Email Provider, your email sending history doesn’t automatically come with you. You need to rebuild your sender reputation from the ground up because ISPs have no record of your previous email behavior under the new service.
  • Rebranding or business acquisitions:

    Changes in your business’s branding or ownership can disrupt your established email reputation. This necessitates a period of re-establishing your domain’s trustworthiness under the new brand or ownership to maintain email deliverability.
  • Transitioning from shared to dedicated IP:

    If you switch from a shared to a dedicated IP address, you’re starting with a clean slate in terms of email reputation. You must build this reputation independently because email providers will now evaluate your traffic separately from any other senders.
  • Addressing deliverability issues:

    If you’re facing challenges with emails not reaching inboxes, warming up your domain can help improve deliverability. This process demonstrates to ISPs or email providers that you’re committed to following best practices and can help reset your reputation.

Understanding these reasons is crucial for implementing a successful warm-up strategy and ensuring your cold email campaigns are a breeze. For those undergoing a rebrand or switching ESPs, resources like Mailreach’s insights on domain warm-up can provide further guidance.

The basics of email domain warm up:  

The process of warming up an email domain is a strategic and measured approach, essential for anyone venturing into the world of email marketing or looking to maintain their presence there.

It’s not just about sending emails; it’s about sending them in such a way that you build a reputation for reliability and trustworthiness. This is achieved by starting with a small number of emails per day from a new IP address or domain and gradually increasing the volume over time.

The goal is to demonstrate to Internet Service Providers (ISPs) that you are a legitimate sender, not a source of spam. You can do this automatically using an IP warm up service tool. 

ISPs are the gatekeepers of email deliverability. They have the authority to filter your email address into the primary inbox, the spam folder, or block them entirely. Their systems are designed to scrutinize your email activity thoroughly.

They assess the volumes of email you send, how often they are opened, whether they are replied to, marked as spam, or deleted without being read. All these factors contribute to your sender reputation—a score that ISPs assign to your domain based on perceived trustworthiness and the quality of your email engagement.

Building a rapport with ISPs is not an overnight task. It requires a consistent and thoughtful approach, starting with sending emails to a small group of engaged users—those who have interacted with your emails in the past and are likely to do so again.

As you slowly increase the volume of emails sent, and as long as engagement remains high, ISPs begin to view your domain more favorably. This recognition is crucial because it directly influences your deliverability and makes sure your emails land in the inbox rather than disappearing into the void of spam filters. 

When to warm up email domain?

Warming up your email domain isn’t just a good idea—it’s a must-do for savvy email marketers and communicators. Think of it like this: You wouldn’t run a marathon without a little training first, right? Similarly, your email domain needs to get in shape before hitting the inboxes hard.

  • Scenarios requiring a warm-up:

    Any significant change in your email sending patterns, such as a noticeable increase in email volume or a switch in your email service provider, calls for a domain warm-up. Additionally, if you’ve been penalized for spam in the past or are starting a new marketing campaign, you’ll need to warm up your domain to rebuild or establish your reputation.
  • Shared vs. Dedicated IP address considerations:

    If you’re moving from a shared IP to a dedicated one, you’ll have no established sender reputation. In this case, warming up is essential to build this reputation from the ground up.
  • New Domains and Subdomains:

    Got a shiny new domain or adding a subdomain to your roster? There’s no history there, no track record. ISPs are wary of newcomers, so you need to prove you’re a good player in the email game by warming up.

Understanding when to initiate a warm-up process is crucial for maintaining the health of your email marketing efforts. For those managing new domains or transitioning to dedicated IPs, Woodpecker’s blog on domain reputation offers valuable insights.

The dos and don’ts of warm up email domain: 

A successful domain warm-up hinges on following best practices and steering clear of common mistakes. Here’s a guide to help you navigate the warmup process:

Best practices for a successful warm up email domain:

  • Gradually increase email volume: 

Begin your email campaign by sending just a handful of emails. This isn’t about making a splash on day one; it’s about setting a steady pace for growth.

  • Segment your audience: 

Your first emails should go to your most engaged subscribers. These are the individuals who regularly interact with your content, and their positive actions will signal to ISPs that your emails are welcome in inboxes.

  • Monitor feedback:

Pay close attention to your email metrics. High open rates and click-through rates are good indicators that your warm-up is on track, while spam complaints are a red flag that you need to slow down and reassess.

Common mistakes to avoid during warm up email domain:

  • Rushing the process: 

Continuously sending emails to subscribers who never open them can harm your sender reputation and increase spam filters. It’s important to clean your list regularly and focus on those who are actually interested in your content.

  • Neglecting engagement:

Sending to unengaged subscribers can lead to low engagement rates, which ISPs may interpret negatively.

  • Ignoring deliverability issues:

If you start to notice deliverability issues, such as an increase in bounces or spam complaints, take immediate action. This could involve further segmenting your list, adjusting your content, or even pausing your campaign to investigate the cause.

By adhering to these dos and don’ts, you can ensure a smoother warm-up process. For further guidance on best practices, consider the insights provided by Warmup Inbox’s post on domain warm-up.

Planning your warmup email domain strategy

A meticulous warm-up strategy is pivotal for anyone looking to establish or maintain a robust email domain reputation. Here’s how to plan effectively:

  • Identifying high-performance emails and engaged audiences: 

    Review your email campaign history. Look for emails with high engagement rates—these are the ones that resonated well with your audience. Use these high-performing emails to start your warm-up.
  • Creating a timeline for the warm-up process:

    Create a schedule that slowly increases the volume of emails over a period of time. This helps you warm up your IP and avoid overwhelming your target audience to maintain a steady build-up of your sender’s reputation.

  • Monitoring email performance metrics:

    Keep a close eye on key performance indicators such as delivery rates, open rates, click-through rates, and spam complaints. These metrics will inform the success of your warm-up and guide any necessary adjustments.

By focusing on high-performance emails and engaged audiences, you can ensure a warm-up strategy that resonates with your recipients.

Execution of the warmup email domain plan: 

Executing a warm-up plan requires diligence and adaptability. Here’s how to implement your strategy effectively:

  • Gradual increase in email volume:

    Kick things off with just a handful of emails. Think of it like dipping your toes in the water before you start swimming. Maybe send out 10 emails on day one, and then bump it up a little bit each day, like adding 10% more.
  • Monitoring engagement and adjusting the strategy:

    Watch how people are responding to your emails. Are they opening them? Clicking on stuff inside? Or are they just tossing them into the dreaded spam folder? If you’re not getting the nods you want, it’s time to tweak your game plan.
  • Dealing with potential issues during warm-up:

    Hit a snag? Don’t just plow ahead. Maybe you need to hit the brakes on adding more emails, or maybe you need to chat with a different group of your audience. The key is to act fast and fix it.

Throughout the execution of your warm-up plan, it’s essential to monitor engagement and be ready to adjust the strategy as needed.

Warm up email domain effortlessly with Inboxy 

In the digital age, where email campaigns are pivotal, ensuring your emails hit the inbox and not the spam folder is more crucial than ever. Using an automated email warm up tool like Inboxy helps you get better open rates and booked meetings, guaranteed.

Inboxy is the only automated email warmup tool that utilizes a private network of headless browsers and AI. 

How Inboxy’s automated email domain warm up works:  

Inboxy simplifies the warm-up process by employing a private network of headless browsers and AI, setting itself apart from services that rely on standard APIs. This unique approach guarantees not just improved open rates but also ensures your emails consistently reach the intended inboxes.

  • Headless Browser Management:

    Unlike other services, Inboxy uses an internal network of headless browsers, ensuring your emails bypass all spam checks with flying colors.
  • Domain Score IQ™

    Your domain’s health is continuously monitored against a database of domains, ensuring top-notch email deliverability.
  • AI-Enhanced Engagement

    Advanced algorithms are at play to create compelling subject lines and content, resulting in an average of 70% open rates and 32% response rates.
  • Scalability for High Volume

    No matter the size of your email campaigns, Inboxy’s service scales to warm up high volumes of emails while maintaining a personal touch.
  • Proactive Email Reputation Management

    Continuous monitoring and adjustments are made to keep your email reputation pristine, avoiding blacklists and ensuring smooth email performance.

How to get started

Step 1) 

Upon signing up for an Inboxy account, we’ll begin the process of bypassing spam filters and boosting your email deliverability. 

Step 2) 

Through the application of sophisticated AI technology, Inboxy simulates authentic email behavior. This includes activities such as opening emails, shifting them from SPAM to the primary inbox, and even responding.

Step 3) 

To ensure the effectiveness of the IP warming process, Inboxy continuously monitors your email performance. If we notice any shifts in deliverability or response rates, our system automatically makes necessary adjustments in the sending patterns.

Setting up with Inboxy is a breeze. In just two minutes, you can sign up, choose your plan, and begin the warm-up process. The service is universally compatible, working seamlessly with any email client, from Gmail to custom SMTP setups.

This is the most efficient and automated way to perform email domain warm up. Now let’s look at the other way. 

Manual warm-up strategy

How to warm up email domain manually 

A manual warm-up is a deliberate process of slowly increasing the number of emails sent from a new or cold email domain to build a positive reputation with Internet Service Providers (ISPs). This hands-on approach allows for close monitoring and quick adjustments based on the performance of each email sent from your email list. 

What you’ll need for manual warm up email domain 

Before you dive in, make sure you’ve got:

  • Engaged contact list 
  • A schedule for sending emails
  • Tools for tracking deliverability and engagement metrics
  • A plan for content variation to keep engagement high

Step-by-Step guide to warm up email domain manually

Day 1: Start with 5 Emails

  • Handpick five individuals who are most likely to read and interact with your emails. Think of them as your test pilots as part of your email program. 
  • Keep a close watch for any turbulence, like bounced emails or spam flags.

Day 2: Increase to 10 Emails

  • Now, send it to 10 recipients. Imagine you’re hosting a small dinner party, and you want to make sure everyone enjoys the meal.
  • The content should be as engaging as the conversation at a dinner table—no one should be checking their watch.

Subsequent Days: Incremental Increase

  • Continue to add more recipients daily
  • Aim for a mix of new and repeating engaged users

Reaching Your Daily Volume Goal

  • Gradually reach your target daily volume over several weeks
  • Do not rush the process; sudden spikes can trigger red flags with ISPs

Tips for effective manual warm-up 

  • Personalize emails to increase engagement
  • Spread out sends throughout the day
  • Use a variety of email content to maintain recipient interest

Pitfalls to avoid during manual warm-up

  • Resist the urge to flood inboxes. It’s the equivalent of overwhelming your new neighbors with too much attention too soon.
  • Never send to people who haven’t invited your emails into their inbox. Consent is crucial.
  • High bounce rates are red flags. It’s like getting a lot of doors slammed in your face. Time to reassess your approach.

By following these steps and keeping a close eye on the performance of your email accounts, you can effectively warm up your email domain manually, setting a strong foundation for your email deliverability rates. Remember, the key is to increase volume gradually and maintain high engagement throughout the process to avoid your email accounts getting filtered for spam.

Maintaining your email domain’s warmth

Maintaining the warmth of your email domain is crucial for ensuring ongoing email deliverability and sender reputation. Here’s how to keep your domain’s reputation hot:

The importance of ongoing warmup 

  • Continuous warm-up activities help maintain a positive sender reputation.
  • Regular sending activity shows ISPs that your domain consistently engages in best email practices.

Strategies for maintaining warmth 

  • Consistent Sending Volume:
    Avoid long periods of inactivity by sending regular communications.
  • Engagement Tracking:
    Keep an eye on open and click rates to ensure your content remains relevant.
  • List Hygiene:
    Regularly clean your email address list to remove unengaged subscribers and invalid addresses.

Monitoring your domain’s health 

  • Regularly review analytics to spot and address deliverability issues promptly.

Adjusting your warm-up plan as needed 

  • If you notice a drop in engagement or deliverability, revisit and adjust your warm-up strategy.
  • Be prepared to scale back and re-warm if you encounter issues like hitting spam traps or receiving complaints.

By implementing these strategies, you can maintain the health and reputation of your email domain, ensuring your messages reach your audience’s inboxes.

How to warm up email domain: wrapping up 

Wrapping it all up, let’s not forget that a solid warm-up strategy is like the backbone of your email domain’s health. Here’s the gist:

  • Start with a manual warm-up, gradually increasing your send volumes of email. 
  • Monitor engagement and adjust your strategy as ne
  • Start by manually sending around 5 emails to high reputation addresses you own or owned by people you know and ask them to open the email, reply, mark as important and remove from spam filters if needed. The next day, send 10 emails following the same process.
  • Maintain your domain’s warmth with consistent sending and engagement practices.

The long-term benefits of a warm email domain include improved deliverability, stronger sender reputation, and better engagement rates. These outcomes are invaluable for any email marketing or outreach campaign.

If you haven’t started the warm-up process, now is the time to begin. With patience and adherence to best practices, your email domain will be set up for success. Remember, the key to a warm domain is not just in the initial warm-up but in ongoing care and attention to your email practices.

Frequently asked questions about warming up email domain: 

In this section, we’ll address some frequently asked questions about the email domain warm-up process.

What is Email Domain Warm-Up?

  • Email domain warm-up is the practice of gradually increasing the volume of emails sent with a new email domain to establish a good reputation with Internet Service Providers (ISPs).

Why is Email Domain Warm-Up Important?

  • It helps in building a reputation with ISPs as a legitimate sender.
  • Warming up prevents emails from being marked as spam, ensuring they reach the recipient’s primary inbox.
  • It’s a critical step for new domains or after significant changes like switching ESPs.

How Long Should You Warm Up Your Email Domain?

  • The warm-up period can vary, but it typically lasts between a few weeks to a couple of months. 
  • Start by manually sending around 5 emails to high reputation addresses you own or owned by people you know and ask them to open the email, reply, mark as important and remove from spam if needed. The next day, send 10 emails following the same process.
  • The schedule depends on your email volume and engagement levels.
  • It’s important to monitor metrics and adjust accordingly, rather than sticking to a rigid timeline.

Can You Warm Up Multiple Domains at Once?

  • Yes, you can warm up multiple domains simultaneously, but each domain should have its own warm-up plan.
  • It’s crucial to maintain separate sending practices for each domain to avoid cross-contamination of reputations.

What Happens If You Don’t Warm Up Your Email Domain?

  • Skipping the warm-up can lead to emails being blocked or sent to the spam folder.
  • It can damage your sender reputation, making it difficult to recover and affecting long-term deliverability.
  • Immediate high volumes of emails sending from a new domain can trigger red flags with ISPs.

Remember, the warm-up process is a key component of your email marketing strategy. It’s not just about avoiding the spam folder; it’s about establishing a lasting relationship with ISPs and ensuring your communications reach your target audience effectively. 

How can I warm up my email domain for free?


You can warm up your email domain for free by manually sending emails and gradually increasing the volume over time. However, for a more efficient and automated process, consider using tools like Inboxy’s Automated Email Warm-Up, which offers a free trial.

Do I need to warm up an email address?

Yes, warming up an email address is important when you start sending from a new address or after making significant changes to your email program. This helps in establishing your email as a trustworthy sender. Learn more about the process with Inboxy’s Automated Email Warm-Up.

What does it mean to warm a domain?

Warming a domain means gradually increasing the number of emails sent from a new domain or after significant changes to your email strategy. This is done to build a positive reputation with ISPs and ensure good deliverability. For more information, visit Inboxy’s SMTP Warm-Up Service.

How do I warm up my cold email domain?

To warm up a cold email domain, start by sending a low volume of emails to highly engaged recipients and gradually increase the number as your engagement metrics improve. For a comprehensive guide, see Inboxy’s blog post on IP warming.

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Erik Paulson

Erik Paulson, CEO of Vendisys, has been an undeniable force in the lead generation landscape for over 15 years. As the visionary behind a conglomerate of successful ventures, Erik's expertise in curating meeting-ready leads has set new industry standards. His insights and perspective are widely sought after and revered in the industry. Through Vendisys and its array of associated entities like Inboxy, he continues to shape and elevate the future of lead generation.