A Step-by-Step Domain Warm-up Guide

Domain warmup steps

Ever wondered why sending thousands of emails with a new domain gets your email address blocked or has a very low delivery rate? A crucial step in saving your emails from getting flagged as spam is to warm up your domain for mass emailing. In this article, we will discuss the step-by-step process one needs to follow to warm up domains.

Table of contents

What is domain warm-up?

Warm-up is like building a good credit score by piggybacking on good transactions. Since most of the spam filters like Gmail, Yahoo & Hotmail work on machine learning algorithms, it's imperative to generate the best open rates and send emails in controlled volumes, to build a good score with the spam filters.

In 2019, Google took more stringent steps from email sending and receiving sides to detect spam emails. The email service provider gives daily sending limits when a user opens a new email account. However, a new account can't use it entirely. Ideally, it takes 8-12 weeks to accomplish maximum deliverability. The warming-up process may seem sluggish and repetitive, but it is essential when you want to escape the dreaded spam folder.

Why do you need to warm up your domain?

Email domain warm-up signals your service provider that you are not a robot or scammer. It becomes crucial when you are preparing a high-volume cold email campaign from a new account.

Given below are the most important reasons you should not overlook the domain warm-up process.

Avoid spam folder

Every domain acquires a reputation that ranges from bad to good. The host considers a new account suspicious from the outset. Hence email warm-up service is needed to ensure that emails reach the receivers' inboxes and build a good domain reputation.

Email throttling

Email throttling implies controlling the number of email messages sent to one ISP or remote server at one time. When a large volume of emails is sent at once without domain warm-up, the receiving ISPs often block these messages because they seem spam.


As per SMTP protocol, a grey-list is a list of email addresses or domain names used by a spam filter to detect suspicious emails. If a message comes from the list's address or domain, it will temporarily be blocked. You must warm-up your domain to steer clear of grey-listing.

In a nutcase, domain warm-up will increase your deliverability and open rates while decreasing your bounce rates.

A step-by-step guide to email domain warm-up

Domain warm-up demands your time and efforts, as it is a long-term commitment. You might want to use your existing company domain to send emails. As it already has a good reputation, it reduces the energy needed for warming it up.

Unfortunately, you might encounter problems and burn your primary domain of everyday business. So, register a new domain and prepare it for email outreach.

Following are the basic checks to ensure that the warm-up builds a good reputation with spam filters:

1. Choose the best data set

The strategy is the key when it comes to warming up a new domain name. Ensure that the best data set is being targeted at the time of warm-up. The best data set i.e. users who would have the maximum probability to open emails would vary from industry to industry.

In the e-commerce industry, users who have opened and clicked the previous EDMs would have the maximum probability whereas, in the job industry, users who have recently signed up would have the maximum probability. Hence it’s essential to understand the business and identify users who would generate maximum opens and not target users who may open and report to spam or not open at all.

Marrying platform activity with email activity and identifying different cohorts like email active & platform active, email active & platform inactive, email inactive & platform inactive, and email inactive & platform inactive is the key.

Also, an alternative hack is to introduce triggers like transaction confirmation, OTP & Forgot Password emails on the new domain name for 5-7 days. This helps build the reputation of the domain and you can start the promotional email warm-up from where you have left off! Eg. if your daily transactional email volume is 2K/day when you start the promotional emails, you can start with a volume of 2K/day!

2. Choose a healthy infrastructure

Ensure that you are assigning IPs that are pre-warmed up and are having a high reputation with Gmail/Hotmail. If it’s a shared IP pool, ensure that you are cleaning up other brands which have poor deliverability.

Also, ensure that the IPs don’t have a reputation of hitting spam traps, and also the database being used to warm-up is clean from spam traps. Spam traps in the database are a negative element and an indication of poor management of data. Lastly, ensure that the domain name used to send emails is at least more than 30 days old.

3. Choose your content wisely

Ensure that the content isn’t banal and personalized enough to entice the users to open emails. Avoid sales-y, content in the early phase if you are just kick-starting your email program-send blog based content that users are interested in reading. Eg. If you are in the travel industry, instead of sending offers, you can send topical blog-based content like places to travel in India in the monsoon.

If you already have had a history of sending EDMs, ensure that you aren’t sending any content which has a prior reputation of landing in spam. Alt, title & map tags should be avoided in the content. Alt & Title tags have keywords that get easily cached by Gmail and other ISPs.

4. Authenticate your email

Account authentication is the first thing required with a new email address. After registering a single domain name for email outreach, follow these steps:

5. Build a definite warmup schedule

To achieve full email deliverability, generate engagement in your warm-up emails. It is vital to have some daily conversations as it is a continuous 8-12 week operation. Having a faithful response base gives the ISP a hint about your legitimacy. Sending the emails at a fixed time and also not sending more than 1.5X the previous day’s volume is essential. Also, the same content shouldn’t be sent for more than 4-5 days.

This is how a typical warm-up plan looks like assuming we are looking at a scale of 300K/day.

How can Mailmodo help with your domain warm-up?

Mailmodo provides you with dedicated service from the moment you sign up. We do regular follow-ups of our clients regarding any issue they might face. How can we offer you the right email warm-up service?

  • Mailmodo is an email marketing platform with proven deliverability. Our clients celebrate an increase in over 225% conversion rates by using interactive AMP emails.

  • Using Mailmodo's email marketing software, you can send bulk and triggered emails helping you to automate the warm-up process.

  • Mailmodo provides a dedicated account manager for enterprise clients to warm up the email domain. Our experts will back you up with any queries regarding the process.

  • Mailmodo's integrated trackers help you monitor your emails' output and export full reports of user activities & campaign results.


The strictness of the algorithm is to maintain a grip on the junk emails. As you are a genuine user, help the system realize that you are not a spammer by following the practices mentioned above. While you are learning and becoming a pro, Mailmodo is here to provide a one-stop solution to warm-up your domain and send interactive emails that help you get more conversions.

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