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How to Warm Up Email Domain :
The Best Tactics to follow in 2021.

Damien Breneliere - MailReach

Damien Brenelière

Co-Founder @ MailReach & Email Deliverability Expert

The question “How to warm up email domain” is very often asked as it is and has always been an unclear subject. Everyone wants to do well and avoid harmful mistakes to get the best email deliverability and at the end, get great email results. In this article, we’ll cover the best tactics to do a perfect email domain warm up.

warm up email domain | MailReach

How to warm up email domain : why everyone is asking? 

How to warm up email domain and how to warm up email account are similar questions asked to pursue the same goal, prevent emails from going to spam.

In 2021, email deliverability is a big concern and it’s more difficult than ever to send emails to the inbox and stay there in the long run while sending email campaigns regularly.

Reaching the inbox is more difficult because of of several factors and updates.

Among all these factors, there are two which are now much more important than before: the engagement level of your domain / email address and having your emails marked as spam.

This means two important things.

Now, if you don’t have enough engagement on the emails you send, you’re more likely to land in spam than before.

Now, when your emails are marked as spam, it damages your reputation and deliverability more than before.

And after all, that’s consistent: if you send emails that no one opens, replies, marks as important or worse, that get reported as spam, that’s a very strong indicator that you’re sending emails that don’t interest anyone.

Then, according to spam filters and email providers, that’d be better for everyone that you land in spam.

This is why email warm up and domain warm up is useful, to help you raise your reputation.

Warming up an email domain consists in gradually increasing the volume sent per day from this domain or email address and generating engagement to raise your sending reputation and show you’re a good sender.

Warm up your email domain and always be warming helps to avoid landing in spam and get good opening rates in the long run.

This is why in 2021 and more than ever, knowing how to warm up email domain can be a game changer to improve your deliverability. 

In the next section, you’ll find precisely how to warm up email domain automatically and how to warm up email domain manually

The two best tactics to do a proper email domain warm up in 2021.  

There are two tactics you can use to warm up your email domain. The first one, which shows the best results without hassle, is the automated way : using an email warm up service. And the second one is manual. 

Tactic #1 : warm up your domain 100% automatically with a service like MailReach.

Warming up your email domain using an email warm up service is raising. A lot of people are using this strategy now as it scales very well and shows great results in terms of efficiency.

How it works

First, you need to create an account on MailReach and then connect the email address you need to warm. By warming an email address you warm the domain associated to this address.

Once your email address is connected to MailReach, the warm up process launches automatically by starting conversations with other inboxes.

Very important, these inboxes your email address talks to are not randomly chosen, MailReach makes your address talk to high reputation inboxes to maximize the efficiency of the warm up. Interesting, right?

MailReach will gradually increase the number of emails sent from your email address for a smooth and effective warm up.

warm up email domain | MailReach

Each warm up email sent from your email address is human and realistic. We send emails that have meaning, no gibberish content that look completely fake. 

Here’s an example of an email sent by MailReach.

warm up email domain example | MailReach

Most of the emails are opened, replied, marked as important and removed from spam when needed. 

All along the process, MailReach adapts to make sure your email address is perfectly warmed and its activity is well balanced.

This automated way allows you to warm up your email domain by following the best practices without having to worry about it nor spend time doing it.

Tactic #2 : doing the warm up manually.

If you’re not ready to pay for an email warm up service, you can decide to do it the manual way. But you need a lot more resources and time, get ready!

What you need

  • Ideally, a list of email addresses you own with a good reputation and aged domains on various providers (Gmail, Outlook, etc).
  • If not, a group of friends ready to reply to your emails.

The theory

Basically, when your domain is new, you want to show the world that you’re a good person who has a lot of friends with great reputation.

To demonstrate this, the best way is to gradually send emails to high reputation addresses and get engagement from them.

By engagement we mean getting your emails opened, replied, marked as important and removed from spam if you were landing in spam (which usually happens sometimes when your domain is new).

A high reputation email address can be :

  • A professional email address on an aged domain (2 years+) that manually sends normal emails (no or very few campaigns) and get a lot of replies.
  • An aged personal email used to send casual emails and get a lot of replies. Typically, your old personal gmail or hotmail address or the ones of your friends and family are good examples of high reputation addresses.


Start by sending manually 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 following days add 10 more emails per day until you reach 100 daily. 

Depending on the daily volume you plan to send, ramp up by adding 30% more emails daily until you reach your goal.

Keep in mind, there’s no exact number on this. The main goal to aim is to have a linear growth curve. Avoid spikes. 


Warming up your email domain is important to build trust with email providers and get good results from your email campaigns.

Using an email warm up service like MailReach can help you automate the process, optimize it and make sure to do it the most efficient way.

But you can also do it with your own hands and expect good results if you manage to generate a good amount of engagement from high reputation email addresses.

In all cases, keep in mind that it’s very important to keep warming your email domain and email address over time and not just doing a one shot warm up to maintain your deliverability in the long run by generating engagement and removing your emails from spam.

Start improving your email results now.