IP Warmup: What It Is, Why You Need It, And How to Use It [+5 Actionable Strategies]

12 min

Let’s talk about email deliverability. In a perfect world, every time we hit that “send” button, 100% of our recipients receive 100% of our content up until the day they consciously choose to unsubscribe from it. Then why do so many email marketing platforms take particular pride in having 99% or even 98% deliverability? Shouldn’t 100% be the golden industry standard? 

Enter sender reputation. Based on numerous factors such as the number of messages sent, your average bounce rate, or the quality of IP associated with your domain. In order to achieve the highest deliverability, you would want to have a positive sending reputation and keep your domain’s IP in check. And that’s where we start talking about IP warming. 

Read more about email deliverability here

If you’re trying to make sense of IP warmup for your business, this guide is for you! We’ll explain exactly what it is and why you would (or wouldn’t) need it. We’ll also go over 5 best practices to get you through the IP warming process.

As a result, you should expect to hit the best deliverability rate among your contacts and, thus, significantly improve the effectiveness of your entire email marketing strategy. 

Let’s start with the basics.

What’s an IP address?  

IP stands for Internet Protocol, which is the set of rules governing how data is sent online. These rules require all devices, routers, and websites to have their own unique address so that information can be sent between them — similarly to how the postal service requires street addresses and zip codes for mail delivery. 

Specifically, an IP address is a string of four sets of numbers separated by periods (e.g., An IP address can be public (internet-based) or private (in-house or local network). 

Dedicated vs. shared IP addresses

A new IP address can be exclusive to the sender, which is known as “dedicated”, or it can be shared with other users. Wondering which one is best? We usually recommend shared IP addresses for low-volume senders who send a small number of emails to a modest list of subscribers. 

Using a dedicated IP address, on the other hand, is a good idea for higher volume senders with more consistent sending frequency. With dedicated IPs, you can focus on building a strong reputation over time, making sure your emails reach customers’ inboxes.  

What’s IP warming?

In a nutshell, new dedicated IP addresses have no sending history — they’re cold. This makes them seem suspicious to receivers like ISPs (Internet Service Providers) and lands them in the dreaded spam folder. 

So, IP warming refers to the warm-up process of a new IP address so that it is trusted by receivers. You can think of it as an extra step in building credibility with the ISPs the same way you use link building to build credibility for your domain rating for SEO.  

Why would you need IP warming?

If you’re using a new, dedicated IP address for email marketing, such as newsletter.example.com, you need an IP warm-up plan. Without it, your emails may look like spam to Internet Service Providers and won’t stand a chance of making it to the recipient’s inbox. 

"Message not deleted" error in Gmail client
Image credit: Gmail

Here’s a quick glimpse behind the scenes of email marketing technicalities: An ISP detects a new email sent from the cold IP address. As it has never seen this domain’s IP address before, the ISP automatically suspects spam. In order to protect the users, the brave ISP throttles email delivery. 

As a result, if you send to 100,000 users right off the bat, the ISP might only deliver the email to 5,000 of those users over the first hour. The consequences could be disastrous for some of the time-sensitive marketing campaigns. 

During this hour, the ISP monitors engagement metrics like open rates, click rates, unsubscribes, and spam reports for the emails it did allow sending. If the metrics are poor, the ISP might choose to relegate the remainder of emails to spam folders instead of inboxes. 

What is more, if this pattern continues, the ISP could make a tough call and blacklist your IP address for good, meaning all of your emails will go directly to the spam folder of your users‘ inbox.

The only time you don’t need IP warming is if you’re using a shared IP address. 

Not sure if you are ready to tackle the IP warmup process on your own? With GetResponse MAX you get access to Assisted IP Warmup and a dedicated Account Manager!

Assisted IP Warmup - GetResponse research

Assisted IP Warmup

Maximize the effectiveness of your email marketing campaigns with our real-data study!

Download guide

IP warming best practices

Now that we know what IP warming is and why you need it, let’s take a look at some of the proven strategies that can get you off on the right foot if you choose to warm up your dedicated IP by yourself. 

1. Start by choosing an IP warming strategy 

A chart demonstrating the number of opens with a standard IP warmup against assisted IP warmup
Assisted Warmup allows even up to 10x the amount of sends compared to a standard IP warmup

There are two main strategies you can use to approach IP warmup: standard IP warming or assisted IP warming

Standard IP warmup 

Standard IP warmup is essentially the DIY approach. With this strategy, you start by sending small volumes of emails, and gradually increase the amount you send each day. During this stage, it’s critical that you demonstrate the real value of your content by only sending highly relevant and permission-based emails. 

This approach helps you to slowly build your positive sending reputation with the ISP and must be done before they can trust you with bulk mailings. If you choose this approach, it’s a good idea to create a schedule to follow for the first month, outlining exactly how many emails to send each day, to what audience, and with which purpose.

Assisted IP warmup

While standard IP warming is definitely an effective strategy, it’s time-consuming. That’s why many email service providers offer some type of automated or assisted IP warming to jumpstart the process. 

For example, qualifying senders using GetResponse MAX are eligible for our Assisted IP Warmup service. With it, we’ll set up a threshold for your dedicated IP to send, automatically adjusting as it progressively builds up your sender reputation. 

If you need to send more messages than the established threshold allows, we will make sure they are deployed automatically from our high-quality shared IP pool. This way, you’ll be able to warm up your dedicated IP gradually for it to be ready to stand on its own.  

Example use-case: You are sending 10,000 emails a day. Our Assisted IP Warmup would start by sending 1,000 from your new IP address and 9,000 from the shared IP pool. Then, it would gradually increase the amount sent from the new IP and decrease the amount sent from the pool until it’s all being sent from your new dedicated address. 

This speeds up the whole process and allows you to send millions of emails from day one without compromising your sending reputation. 

2. Carefully maintain a good sender reputation 

Sender reputation is based on the relationship between a sender and a receiver (typically represented by ISPs). The better your reputation the higher your deliverability rate will be, and vice versa. 

As you could’ve guessed, the best way to boost your sender reputation is to actively monitor factors that affect deliverability. These include but are not limited to keeping an eye on the following metrics: 

  • How many messages you send and how often
  • What percentage of your messages get flagged as spam 
  • How many (if any) of your receivers blocklist your emails 
  • Do any of your emails land in spam traps 
  • Customer engagement metrics like bounce rate, open rate, click-through rate, etc.

3. Send the most engaging content possible

Speaking of metrics like open rate and click-through rate, during the IP warmup stage, it’s crucial to make sure that the content you are sending is genuinely relevant and engaging to the recipient. 

The more emails your customers open the better your sender reputation becomes. If your emails are ignored (or worse, flagged), ISPs will knock you for it and it will take much longer to warm up the address. 

Here are 5 tactics to get more engagement in less time

1. Add personalized, subscriber-specific content to your emails

Automated, personalized emails have an average open rate of 44% and a click−through rate of 10%. Use custom fields and tags to collect valuable information about your customers. Then, fill your contact cards with useful data to improve the relevance and personalize your email content.

Learn how personalized solutions drive higher ROI with our Forrester case study!

2. Use social proof in your emails to build trust

It’s human nature to seek out the opinions of others before making a decision. That’s why regularly using customer testimonials can generate 62% more revenue for your business. 

GetResponse customers can use the social proof section featured in the templates to add testimonials to their emails with ease. 

3. Encourage subscriber action early on

Emails with a single call-to-action (CTA) increased clicks by 371%. So, it’s a good idea to design your emails with a specific CTA in mind and design your email template in such a way, that the CTA attracts users’ attention. Highlight it with a different color, create a branded button, or use a graphic-based CTA to maximize conversions.

4. Make sure your email looks great on all devices

Mobile devices account for 34% of message opens 47% of message clicks. So, don’t forget to optimize your email templates for mobile in order to increase conversions and improve overall performance. 

5. Get interactive with your email content

People pay more attention to video than any other type of content. In fact, emails with links to the Vimeo hosting platform have an average 39.67% open rate and 8.83% click-through rate.

Unfortunately, not every email automation tool allows for video content to be directly included in the email body, so it’s worth investing in those that do. 

With that, let’s return to our best practices to warm up IP addresses.

4. Keep your email list squeaky clean 

Even if you create the most engaging content on the planet, it’s not going to do you any good if you send it to an invalid or spam email address. In fact, it’s going to do a lot of harm. At the end of the day, your email strategy is only as good as the contacts it is aimed at.

Not every address signed up to your contact list is actually worthy. In fact, you’ve probably gathered quite a few spam, invalid, or dangerous email addresses. These undesirable contacts can cause low open and click-through rates, negatively affect your deliverability or result in increased bounce rates — ultimately downgrading your sender reputation.  

Apply these two strategies to keep your list as clean as possible

Regularly clean out low-quality and invalid emails 

While it sounds like a lot of work, thanks to the growing popularization of email marketing automation tools, there are plenty of services that can take care of email verification and validation for you. 

Use a confirmed double opt-in process

We always say email list quality beats quantity every time. But we meet many marketers who are scared to use confirmed opt-in. They worry it will make their list smaller or make people mad about having to go through an extra step. 

However, our data suggests otherwise. When you compare the average email marketing results by industry with the use of double opt-in by industry data, you can see that industries that use confirmed opt-in more often usually outperform those that don’t.

Still skeptical? This article goes into more detail on why it’s worth using double opt-in

5. Segment your marketing and transactional emails

Many mailbox providers now advocate that you separate your marketing emails from your transactional emails in order to maintain independent sending reputations and deliverability rates.  

If you’re not too familiar with the term “transactional email,” it refers to a one-on-one message that’s sent in response to a customer action and contains specific account information. Examples include order confirmations, password resets, shipping notifications, and more. 

It’s critical that your transactional messages make it to the customer’s inbox since they’re often waiting for them to arrive. And this is where segmenting comes into play. 

By creating separate subdomains for your transactional emails and your marketing or promotional emails, you protect your ability to keep sending transactional messages even if you run into issues with your marketing email deliverability. 

Segmenting also helps troubleshoot issues in the future because you can isolate which campaigns or data sources contributed to reputational damage.

IP warmup FAQs

IP warming is a complicated subject and can be hard to wrap your head around. Here are a few more answers to the frequently asked questions on the subject. 

How do you warm up an IP address?

In a nutshell, you warm up an IP address by sending a small amount of high-quality, permission-based emails and gradually building up to bulk mailings. 

Do you need to warm up a shared IP?

One of the biggest benefits of a shared IP is exactly the fact that you don’t need to warm it up as it has a continual pool of users. 

However, the downside is that other senders may potentially affect your own sending reputation. Since you’re not the only party contributing to your domain’s reputation you don’t have full control over it. 


Hopefully, you’re feeling more confident and informed about IP warmup for your business. Remember, that if this process seems a little too complex for you, you can always opt-in for the Assisted IP Warmup with GetResponse MAX and benefit from bulk sending without having to wait for your domain to build up its sender reputation. 

Anna Kvasnevska
Anna Kvasnevska
Anna is a content marketing specialist and a proud member of the GetResponse team. With more than 5 years of experience in content creation, as well as her intercultural background and cross-industry perspective, Anna is happy to share her insights into the latest updates from the world of online marketing, eCommerce, and technology. Connect with Anna on LinkedIn.