How to Easily Warm Up Your Domains Before Outreach in 2025

A domain with a high reputation can make all the difference to your sales and marketing campaign.

So, if you’re reading this blog, it means you might be looking for a surefire way to warm up your email domain and guarantee maximum email deliverability.

And that’s exactly what I’m here to share with you!

Now, while it might take longer to warm up an entire email domain compared to a single email account, the good news is that the process is very similar.

In this blog, I will guide you through the step-by-step process of warming up your email domain.

I’ll also share with you a guaranteed method that assures high email deliverability: automated email domain warm-up.

Let’s get started!

How to Warm Up Your Email Domain: Step-by-Step Process

Email domain warm-up can seem like a challenging task: while you want to unlock maximum deliverability, you also want to ensure that you’re following a process that guarantees results.

And that’s exactly what I’ve got for you: a step-by-step process you can rely on to unlock the peak deliverability for all the email accounts associated with your domain.

Here’s how it works:

1. Make Sure You Have Set Up Your Domain and Email Accounts Properly
2. Let Your Domain Age for a Few Days
3. Start Warming Up Your Domain
4. Gradually Increase Sending Volume
5. Keep Inbox Engagement High
6. Monitor Deliverability Metrics

1. Make Sure You Have Set Up Your Domain and Email Accounts Properly

Before you start warming up your domains (email accounts), there are a few things I recommend you get done:

1. Set Up SPF, DKIM, and DMARC Records
2. Forward All Your Secondary Domains to Primary Domains
3. Create Professional-Looking Inboxes with Profile Pictures

Set Up SPF, DKIM, and DMARC Records

In 2024, all major Email Service Providers (ESPs) have updated their policies and require users to set up three authentication records for their email accounts.

These include SPF, DKIM, and DMARC. 

If you’re planning to use your domains to send mass outreach or cold emails, I highly recommend that you set up all three records before starting your domain warm-up!

Forward All Your Secondary Domains to Primary Domains

The second thing you should do is forward your secondary domains to your primary domain.

Here’s why 👇

If one of your recipients decides to look up your secondary domain (and trust me, some will), you want them to land on a legit-looking, branded website—not a blank page or an error.

Create Professional-Looking Inboxes with Profile Pictures

The last step before you can confidently start warming up your domains is to create professional inboxes with customized profile pictures of your employees.

From what I’ve seen, email accounts that have a picture associated with an actual person have consistently achieved higher open and reply rates.

This is because recipients can associate your email communication with a name and a face and are, therefore, more likely to trust it!

2. Let Your Domain Age for a Few Days

Okay, so once your email accounts associated with your domain are set up and ready, it’s time to take a deep breath and let your domain idle for a couple of days.

Yes, idle, don’t do anything… There’s a good reason behind this 👇

If you start sending emails immediately, ESPs are going to suspect you of suspicious activity.

So, wait for 2 to 3 days before initiating a domain-wide warm-up exercise!

3. Start Warming Up Your Domain

Once the waiting period is over, you can finally start doing what’s necessary: sending warm-up emails to increase your deliverability.

Here’s how I recommend you proceed with it:

1. Start Sending Warm-Up Emails
2. Focus on Real, Conversational Content

Start Sending Warm-Up Emails

Start by sending 5–7 manual emails/day to colleagues, friends, and other known people. 

Also, I highly recommend that you send warm-up emails exclusively to B2B email addresses. 

These addresses are far more likely to have a higher sender reputation, and they will help you quickly increase the sender reputation of your email accounts.

Focus on Real, Conversational Content

Now, don’t just send “Hi” or “Test email” and call it a day.

That’s not going to cut it.

You need to sound human and act human.

Why? — Because ESPs monitor engagement rates like reply rates and use them to judge whether your emails are valuable.

So, if no one is replying and there is no conversation… ESPs think you’re sending junk.

I know what you’re thinking:

 “How am I supposed to maintain real conversations every single day?”

Totally valid. That’s where automated email warm-up services come in.

These tools help you send personalized warm-up emails and even receive replies from trusted, high-reputation email accounts—automatically.

This way, your engagement looks authentic (because it is), and your domain reputation will increase steadily.

4. Gradually Increase Sending Volume

Consistent is key when it comes to warm-up. 

This is because sending too many emails too soon is a huge red flag for most ESPs, as they closely resemble the sending patterns of spammers and phishers.

So, if you want to do the opposite of ruining your domain reputation, I strongly suggest you gradually increase your sending volume and also maintain a consistent email-sending pattern.

5. Keep Inbox Engagement High

As we’ve discussed above, ESPs take email engagement very seriously: for them, it’s a sign that you’re delivering valuable email communication to their users. 

In short, the better your engagement, the more they’ll trust you as a source of secure and valuable email communication!

So, once your domain warm-up is in full swing, you need to ensure that you’re engaging in meaningful email conversations.

This means:

• Replying to emails you receive
• Marking specific emails as important
• Taking wrongly flagged emails out of the spam box
• Continue past email conversations even after the warm-up phase

I know what you’re thinking: completing this process for even one email sounds like a huge challenge, let alone an entire domain!

And that’s where an automated email warm-up platform like TrulyInbox can help you!

It takes all the steps we have discussed above with a key difference: it automates the entire process, so all you have to do is keep monitoring your email deliverability metrics!

6. Monitor Deliverability Metrics

The last (and one of the most important) step in domain warm-up is tracking email deliverability metrics.

After all, the entire reason you’re warming up your domain is to ensure that you get a high domain and email sender reputation at the end!

Here are the key deliverability metrics that I suggest you monitor during the warm-up phase:

• Inbox placement rate
• Hard bounce rate
• Spam complaint rates
• Reply rates
• IP and Domain Reputation

If you’re wondering how to monitor such metrics, I recommend using a free platform like Google’s Postmaster Tools. 

By constantly monitoring your deliverability metrics, you can immediately take corrective action if you notice a spike in the spam rate or a decrease in your sender reputation.

How Long Does it Take to Warm Up Email Domains?

The short answer: Roughly 4 to 5 weeks.

Here’s a more detailed explanation:

You simply can’t rush the warm-up process – you must send emails slowly and gradually, or else ESPs may flag you for malicious activity.

Doing the domain warm-up manually can be a very demanding process, but it is still doable. (I honestly don’t recommend it though!)

If you have multiple domains and multiple email addresses and still want to do it manually, well, good luck getting it done by the end of the year!

For such a situation, I strongly suggest you use an automated email warm-up platform like TrulyInbox — You can connect unlimited email accounts from any domain and warm them up automatically!

Is Email Warm-Up Different From Domain Warm-Up?

This is one of the most common questions I get asked… 

Is email warm-up different from domain warm-up? And if so, what exactly is the difference?

While email warm-up is only concerned with one email account, email domain warm-up involves warming up an entire domain, which can have multiple email accounts.

So, if you warm up an email account, its sender reputation will increase slowly, but the domain reputation will stay the same!

If you want a high sender reputation for all email accounts + domain reputation (the perfect combination for high email deliverability), then you should do a domain warm-up. (warming up all email accounts associated with a domain)

Email Domain Warm-Up: Best Practices for Maximum Deliverability

It’s one thing to undertake email domain warm-up, but quite another to get it right! 

And since we’ve already explored the step-by-step process of how to warm up email domains, let’s now understand how you can get assured results from your warm-up exercise:

1. Authenticate Your Domain Before You Start
2. Avoid Links, Attachments, and Spammy Language Early On
3. Use Consistent Sending Behavior
4. Monitor and Adjust Based on Deliverability Signals
5. Use an Automated Warm Up Platform

1. Authenticate Your Domain Before You Start

The one thing that I have personally learned the hard way is that warming up unauthenticated email domains leads to extremely poor results. 

On the other hand, email accounts with comprehensive authentication records have a much higher chance of increasing your deliverability rate and the overall domain reputation.

In short, you should never start an email domain warm-up without first authenticating the email accounts in your domain.

2. Avoid Links, Attachments, and Spammy Language Early On

ESPs really don’t like it when you send cold emails with links, attachments, or HTML scripts, especially if you have a new email account or domain.

This is because such emails display the classic signs of malicious content that the ESPs associate with fraudulent email-sending patterns.

So, you should never use links (even in the signature section), include attachments, or use spammy language for warm-up emails. 

I recommend sending simple, text-based emails to discuss industry trends, exchange information, and invite replies from your recipients. 

3. Use Consistent Sending Behavior

The best way to warm up an email domain is to take a slow-and-steady-wins-the-race approach. 

Simply put, you should avoid changing the number of warm-up emails you’re sending through any email account in your domain.

Again, the reason behind this is that sudden changes in sending patterns are likely to trigger ESP filters and could even put you on spam blacklists!

4. Monitor and Adjust Based on Deliverability Signals

I also highly recommend adopting a proactive approach to email domain warm-up. 

Carefully monitor your deliverability metrics, and take immediate action if you see a spike in bounce rates, an increase in spam complaints, etc.

I recommend you pause your warm-up and reach out to the support team; they’ll help troubleshoot any problem you may have.

Only applicable if you’re using a platform like TrulyInbox.

If not, you’re on your own to run a deliverability audit and find what’s wrong. (A real hassle 😖)

5. Use an Automated Warm Up Platform

The last thing I recommend is that you always use an automated platform to warm up your email domain. There are three reasons for this:

• It will help you free up resources and time you can dedicate to more strategic tasks
• It is a method of email warm-up that guarantees immediate support and results
• It will enable you to easily monitor your deliverability metrics in real time

Start Warming Up Your Email Domain and Land in Inboxes!

There you go—domain warm-up explained in 6 simple steps!

Now, all that’s left is to pick a cost-effective, easy-to-use platform like TrulyInbox and start getting your domain ready for outreach.

Good luck!

Email Domain Warm-Up: FAQs

1. Does email domain warm-up actually work?

Yes, in my experience, email domain warm-up can increase your email deliverability to more than 95% within 4 to 5 weeks. However, the only way to guarantee such results is to use an automated email warm-up service that helps you send emails to professional email accounts with a high sender reputation.

2. Can I warm up my domain for free?

Yes, you can warm up your domains for free — by doing it manually. However, the downside is that you might have to spend a lot of time and effort on a process that doesn’t guarantee a high domain reputation.

3. What is the best warm-up tool I can rely on to warm up my domain?

Having tried and tested several email warm-up services on the market, I think that TrulyInbox is the best warm-up tool you can rely on to warm up your domain. It is an easy-to-use platform that works with all the top ESPs out there, offers flexible pricing plans, and is very effective at increasing domain-wide email deliverability rates.