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Trust isn’t something that’s developed in a day. Strong customer relationships are built on a foundation of smart, seamless, and reliable communication over a period of time. 

The same theory goes for a brand’s relationship with ISPs. They don’t only keep a check on what kind of emails you send to your customers but also make sure that you send quality messages to your subscribers. 

Simply put, ISPs will allow you to send messages only when you gain their trust by not spamming your customer base with irrelevant and unwanted emails.

However, if you don’t have any prior sending behavior or history for reference, it becomes difficult for ISPs to decipher whether you are an authentic sender or not. Therefore, it becomes imperative for you to garner their trust and confidence by proving that you are a genuine email marketer willing to provide value to their customer base. This is where IP warming comes in handy. 

Read more: Email Marketing 101 for Small Business

IP warm-up, as the name itself suggests is a process of warming up your email marketing strategy to improve your sender reputation. 

You can leverage IP warm-up by slowly and steadily increasing the volume of your email sends. The whole warming up process usually takes 4 to 6 weeks. However, the whole procedure can take a longer time depending on factors such as mailing frequency, your brand’s pre-determined monthly email volume along with your overall email list hygiene. 

To put it in other words, IP warm-up is all about adding campaign volume in the new IP address in a gradual and systematic way. 

Remember, IPs are all about protecting their users from any kind of unsolicited and unwanted emails. That’s the reason they always proceed with caution when dealing with new IPs with no prior history. 

All in all, if your sender reputation isn’t good, ISPs might report your messages to the spam folder or even worse, block you from sending any emails. So, make sure you warm up your IP address properly. 

Here are a few tips that you must consider before taking the IP warm-up plunge.  Take a look.

Be cautious from the beginning

Remember, correcting a bad reputation can be a daunting task. So, don’t take an aggressive approach when sending your emails. With sending reputation being tracked every 30 days, it can take you a lot of time, approximately 4 or more weeks to rebuild your reputation. 

Read more: 7 Ideas for Targeted Email Marketing

Don’t fall into the IP rotation business

Owning a dozen IPs is not a good thing. If you think you can send a large volume of emails by switching IPs, think again. If the ISPs find it out, they will end up blocking your entire IP range. So, instead of rotating your IP, it is better to warm up your IP properly and send messages every day. 

Leverage data to improve your strategy

ISPs keep a close look at how you are responding to your recipients. Consequently, if you leverage customer data in a proper way, you will be able to respond to your subscribers. Further, it will also help you in optimizing your campaign to suit the need of your subscriber base. 

Make use of the marketing email properly

Since ISPs view transactional email as something that is based on customer’s trigger behavior, it gets a little more space compared to marketing emails. Therefore, you need to be cautious while sending marketing emails. Using two dedicated IPs, one for transactional email and the other for marketing can help. . 

Now, since you know the tips to ace your IP warm-up process from the beginning, here are some of the best IP warm-up practices that can further accelerate the whole process and take it to the next level. 

Streamline your email infrastructure and authentication pieces

Before you begin your IP warm-up process and start sending emails, make sure your infrastructure and authentication pieces are all tidied up together. This includes updating your DNS records, signing with DKIM, passing SPF and protecting your system. 

Get hold of the feedback loops

IP warm-up is a crucial time for your business. So, while you are trying to build up a sender reputation for your brand, make it a point to avoid sending your emails to customers who don’t want to receive it. After all, you wouldn’t want to harm your sender reputation with additional complaints. 

In this context, you can make use of feedback loops. These will help you in suppressing the email addresses that have marked you as spam from any of your future email campaigns. 

Send content to your brand’s most engaged recipient

Sending emails to your most engaged users can take your IP warm-up campaign to an altogether new level. If you send your emails to the subscribers who are more likely to open, click-through, and reply to your emails, the chances of your email being deleted or marked as spam becomes less, thereby improving your sender reputation to a great extent. 

All you need to do is follow a consistent warm-up schedule and send emails to your active and engaged subscribers first. 

Find what your brand’s most engaging content is

You must analyze and keep a close look at the content that resonates the best with your customers. 

From a promotional email to a discount coupon or a weekly newsletter, make content that subscribers look forward to receiving and reading regularly. 

Maintain a clean email list

Using a clean email list can play a crucial role in making your IP warm-up process successful. So, keep a check on your email list and engage with only valid email addresses that have not bounced. 

Also, make sure the contacts you are targeting have connected with your brand in the last six months. In short. don’t contact any unsubscribed address as they can affect your sending count. All you need is an email list that has active subscribers, customers and interested parties. Never make use of unengaged subscribers or purchased lists. 

Configuration is the key

Configuring your email list is a critical aspect of the IP warm-up process. With each ISP having its own introduction metrics, a configuration can help you target your customer base in accordance with each ISPs capacity. 

For instance, if you have a target audience of 100,000 for 15 days for carrying the warm-up process, you can configure each of the ISPs depending upon their capacity. Here’s how you can do it. 

Google Mail:

  • Day 1 – 5 emails sends
  • Day 2 – 10 email sends
  • Day 3 – 20 email sends


  • Day 1 – 500 email sends
  • Day 2 – 1,000 email sends
  • Day 3 – 1,500 email sends


  • Day 1 – 500 email sends
  • Day 2 – 500 email sends
  • Day 3 – 500 email sends
  • Day 4 & 5 – 500 email sends
  • Day 6 – 1000 email sends

Go for segmentation

It is also important to create a segment for IP warm-up based on per ISP per day. Here’s an example of an email segment for the same.

Day 1 Segments

  • Gmail Day 1
  • Google Day 1
  • MS365 Day 1
  • Other Day 1

Day 2 Segments

  • Gmail Day 2
  • Google Day 2
  • MS365 Day 2
  • Other Day 2

Day 3 Segments

  • Gmail Day 3
  • Google Day 3
  • MS365 Day 3
  • Other Day 3

Work on ISP blocks

At times, your email send behavior can trigger the ISP to blacklist your email address. In these cases, your messages will land in the spam folder even if your subscriber is highly engaged. 

You need to understand what these blocks are all about. Are these about your reputation? Are they affecting your deliverability? Once you know it all, you can request the ISPs to remove you from their blacklist, helping you avoid these situations in the future. 

Monitor your email metrics

You should make email reporting an integral part of your overall warm-up campaign. It will help you analyze and measure various email metrics such as delivered rate, bounced rate, open rate, click rate, spam rate etc. 

Read more: 5 Emails You Should Send Today

Wrap up

An impeccable IP warm-up process will help you send and get relevant messages delivered to your customers’ inbox. In short, IP warm-up, if done the right way can help you give your customers a targeted, personalized and contextual experience. 

So,  follow the above-mentioned strategies and see how it helps you in setting up a seamless IP warm-up process while assisting you to establish a positive sender reputation across all the ISPs. 

If you are still looking for more insights into IP warming, head to the infographic by Email Uplers: Smart IP Warming: The First Stride of Email Deliverability.

IP warming infographic from Email Uplers that goes over the steps to warm up an IP for email success in partnership with Selz ecommerce for business growth


About the author

Kevin George

Kevin George is Head of Marketing at Email Uplers, one of the fastest-growing custom email design and coding companies, and specializes in crafting professional email templates, PSD to HTML email conversion and free responsive HTML email templates in addition to providing email automation, campaign management, and data integration & migration services. He loves gadgets, bikes, jazz and eats and breathes email marketing. He enjoys sharing his insights and thoughts on email marketing best practices on his blog.