How to Warm Up an Email Domain?

Your email domain is simply the second half of your email address – the part that comes after the @ symbol.

For personal email addresses, the domain is usually a well-known webmail provider, such as,,, or

However, most companies and businesses have their own email domain. Having its own email domain makes a business look more professional. It also facilitates branding and makes it easier to organize marketing campaigns.

Furthermore, a distinct business email domain allows customers, suppliers, and investors to easily find the right person to email within the company, since there is a consistent naming convention for the email addresses of different departments and staff members.

When you get a new email domain for your company, however, you must be super careful to maintain (and preferably improve) its domain reputation. The domain reputation of your business email is extremely important for the success of your outreach and marketing efforts.

And the best way to maintain an excellent domain reputation is by warming up your email domain before you start using it for cold outreach campaigns.

You can warm up your email domain manually or through an automatic email warm-up service. The key is to send out small batches of high-quality, natural-sounding emails to verified recipients. You must then ensure that your emails are frequently opened, read, answered, and marked as important by the recipients.

Article by Philip Ilic,
B2B Growth Specialist.

What is Domain Reputation?

Domain reputation is one of the two main aspects of your email sender reputation – the other one being IP reputation. As the names suggest, your IP reputation is tied to your computer or device, while your domain reputation is tied to the business domain name.

Webmail providers – such as AOL, Gmail, and Outlook – calculate your domain reputation on a scale of 0 to 100. The higher the domain reputation, the more trustworthy your emails are considered to be.

A high domain reputation has several advantages – the chief amongst them being good email deliverability.

When you send out an email, the webmail provider has to decide whether to put it in the recipient’s inbox, their Promotions tab, or in the spam folder.

The sender’s domain reputation is one of the main factors that affects this decision.

A high domain reputation tells the webmail provider that the email being sent probably isn’t spam. Past recipients have interacted positively with the emails sent from this domain, so future emails should be placed in the intended recipient’s inbox.

A poor domain reputation has the opposite effect. It tells the webmail provider that past recipients have not interacted positively with the emails sent from this domain. Hence, these emails are probably spammy and not valuable. They should either be blocked from delivery or placed in the spam folder, once delivered.

If your domain reputation is low enough, all your business emails will land in the spam folder of your intended recipients. They might even be blocked outright. Naturally, this will prevent people from seeing your emails, and hence, your email marketing efforts will not have the expected ROI.

To prevent this from happening, make a note of the main factors that might affect your business’s email domain reputation.

  • How often your emails are opened and read by your recipients.
  • How many emails are sent from this domain every day or week.
  • How often recipients delete your emails without opening them.
  • How often recipients mark your emails as spam.
  • How often recipients interact positively with your emails, such as by replying to them, clicking on links, forwarding them, or marking them as important.
  • How many of your emails bounce, as a result of being sent to unknown users.
  • How often your emails hit the spam traps set up by the webmail provider.

This is not a comprehensive list, since webmail providers are quite secretive about the exact criteria used to calculate your domain reputation. This secrecy is intended to prevent people from ‘gaming the system’ to try and bypass the spam filters.

However, slowly warming up a new email domain is one of the most well-known, straightforward, and reliable ways to keep your domain reputation high. So, let’s dive straight in and learn more about what it means to ‘warm up’ your domain, and how you can do it.

Why You Need to Warm Up Your Domain?

If you start sending out thousands of emails from a new domain, this will greatly hamper your email deliverability, ensuring that your emails are frequently flagged as spam.

This is because webmail providers are wary of spammers and are always trying to protect their users from unsolicited and unwanted communication. Setting up a new domain, only to start sending out thousands of mass emails, signals to the webmail provider that you might be a spammer.

If these emails are frequently ignored by the recipients (or worse, marked as spam), then this will almost certainly destroy your domain reputation and prevent you from reaping the benefits of a good email marketing campaign.

These problems can be avoided by warming up your new domain before starting your email marketing campaign.

Domain warmup involves a process of slow reputation building – a history of positive email interactions with multiple recipients, while sending out emails in controlled volumes.

High open and click rates (and other types of engagement) tells webmail providers that your emails are valuable and interesting to those who receive them.

This makes your domain more trustworthy, from the perspective of the webmail provider. As a result, emails sent from this warmed up domain are more likely to be placed in the inbox rather than the spam folder.

So, how do you go about warming up your new email domain?

Two Ways to Warm Up Your Email Domain

There are, presently, two main ways in which you can warm up your email domain, to improve your deliverability. These are as follows:

1. Manual Warmup

This is the cheaper (but more time-consuming) way of warming up a new email domain.

In order to manually warm up a domain, you need to regularly send emails to high-reputation email addresses and receive positive engagement from them.

Positive engagement can mean a number of things, including:

  • The email being opened and read by the recipient.
  • The recipient sending a reply to your email.
  • The email being marked as important.
  • The email being forwarded to another person.
  • The email being removed from the spam folder, if it has landed there.

All of these things will send a message to the big webmail providers – that lots of people engage regularly with your emails and are interested in what you have to say. In other words, you are not a spammer.

For this, you should have a number of friends or colleagues with high reputation email addresses, who are willing to open, read, and reply to your emails on a regular basis.

A high reputation email address can be of two types:

  • An old, well-used personal email address that is used to send normal emails, and typically receives lots of replies.
  • A professional email address on a domain that is at least two years old. This professional email account should be largely used for normal, day-to-day email communication, rather than for mass email campaigns.

You can start off by sending a small handful of emails to these high reputation accounts each day. Initially, you should send no more than 5-7 emails per day, while making sure that the engagement level remains high. If necessary, ask your friends and family to read and reply to the emails sent from this new domain.

Gradually, you can increase the number of emails you are sending per day. After a week, you can start sending 15-20 emails per day. If engagement levels remain consistently high, you could keep adding 10 emails per day, until you’ve reached a healthy send volume of about 100 emails daily.

Now, your new domain has been completely warmed up. It is finally ready for the mass email marketing campaign that you’ve been preparing for, all this time.

While there are no exact numbers, you will know that the manual warmup tactic is working if none (or very few) of the emails sent to your friends, family, and colleagues end up in the spam folder.

2. Automatic Warmup

If you want an efficient, scalable way to warm up your new email domain, then you should opt for a reputed email warmup service or website. Such websites – like Lemlist, Woodpecker, and MailReach – offer users the option to automatically generate activity on a new email account.

This tells webmail providers that you are a trustworthy sender, without you having to spend hours sending emails back and forth to your friends and family.

By automatically generating email activity on your new account, the service helps warm up not only that particular email account, but also the domain associated with it.

You must now be wondering how exactly an email warmup service works. Well, here’s a step-by-step guide on how these websites can help you automatically warm up your new domain.

  • First, you will need to create an account with your chosen domain warm-up service. Some options include Lemlist, GMass, Mailwarm, MailReach, etc.
  • Next, you will need to connect the new email address (the one you want to warm up) to the domain warm-up service.
  • The email warm-up process will now be launched.
  • In this process, the email warm-up tool will automatically start email conversations with other, high-reputation email addresses around the world.
  • Initially, the email warm-up tool will only send out a few emails each day to these high-reputation inboxes around the world.
  • These inboxes are all owned by the same service provider (or its associates), thus ensuring that each email sent to them will receive sufficient positive engagement. These automatically-sent emails will be opened, read, and replied to, which will help build up the reputation of your domain. All without you having to spend any time on the warm-up process.
  • Gradually, the number of emails sent per day from your email address will be increased. This larger volume of emails will also receive sufficient engagement and attention to warm your new domain in a smooth and efficient manner.
  • The best email warm-up services ensure that these emails – that are automatically generated and sent from your new domain – look realistic and human. The automatic email conversations between the different inboxes are designed to look meaningful and comprehensible, not random gibberish that can be easily identified as fake.
  • The email warm-up tool will essentially emulate the behavior of an individual reaching out to various people about business topics. So, when these emails receive a lot of replies and engagement, it will look organic and increase the reputation of your new domain.
  • The email warm-up tool will also ensure that the activity in your new domain is well-balanced. In other words, not all the emails sent from the new account will be opened at the same time or replied to in the same way. Different inboxes will engage differently with the emails, such as opening and reading it, marking it as important, or replying to it at various points of time during the day.
  • This will ensure that the webmail providers do not find the activity from your new domain suspicious in any way.

An automatic email warm-up service of this type is definitely the most efficient and reliable way to warm up your new domain. However, such a service can be expensive, and may even seem rather complicated, especially at first.

Therefore, you should do some research about the best email warm-up tools out there, as well as the features and payment plans that each of them offers. This will help you choose the one that best suits your budget and business needs.

The Best Tools for Warming Up Your Domain


Woodpecker’s warm-up and recovery feature is available to all premium users, at no extra cost. Along with all the other email automation services that Woodpecker offers, it also allows users to automatically warm up their new email domain and improve their sender reputation.

The recovery feature is meant to help users ‘recover’ their sender reputation, in case it goes downhill. You simply need to connect your email account to Woodpecker and turn on the mode you need – domain warmup or reputation recovery. After this, Woodpecker will handle the entire email warmup and reputation building process automatically.


The email warm-up tool provided by Lemlist is known as Lemwarm. It is used by more than 20 thousand people across 100 countries around the world. Therefore, it has no need to set up or use fake email addresses to build your sender reputation.

Instead, the many users of Lemwarm can (automatically) exchange emails with each other’s inboxes, thus ensuring that every email account being used during the domain warm-up process is both real and currently active.


This domain warm-up tool emulates thousands of leads and prospects interacting organically with your emails. All this activity and positive engagement tells the webmail providers that your new email domain only sends out messages that are important and interesting to the recipients.

Once you sign up with Mailwarm, your email account will automatically send an increasing number of emails every day to more than a thousand Mailwarm accounts. These emails will then be automatically opened, read, marked as important, and replied to. Mailwarm will also provide you with daily insights about all activity from your new domain or email address.


You can use GMass to automatically warm up your Gmail or G Suite email address. This tool will minimize the risk of your email account being suspended by Google for spammy activity. Apart from the normal features offered by other domain warm-up tools, GMass offers certain extra benefits. These are as follows:

  • One-click setup process that does not require any passwords, usernames, or other form of authentication. You simply need to connect the new email address to GMass and let the automatic warm-up process begin.
  • GMass analyzes the sending patterns of the email account being warmed up, in order to determine what volume of emails should be sent out initially and how quickly it should be ramped up.
  • To make the email interactions seem more natural, GMass creates multi-message threads of several back-and-forth replies, rather than a single email followed by a single reply.

It is free to use for anyone who uses Gmail or Google Workspace for their business emails.


This domain warm-up service works by consistently engaging with your emails, in a balanced manner and on a daily basis. It automatically starts conversations with thousands of valid, high-reputation email accounts, ensuring that each email sounds natural, human, and makes complete sense.

Once these automatically-generated emails are sent out, they are opened, read, answered, and removed from spam, when needed. MailReach constantly monitors the evolution of your sender reputation and email deliverability. You can easily keep track of your deliverability score (as well as other metrics) on their dashboard.

Benefits of a Warm Email Domain

Properly warming up a new email domain has many benefits, particularly if you are a business owner or marketer planning to use it for your cold outreach campaigns. Whether it is automatic or manual, a balanced and efficient email warm-up process will–

  • Build trust with webmail providers
  • Improve your email deliverability
  • Help you get better results from your cold email campaigns
  • Keep your messages out of the spam folder
  • Keep your domain out of email blacklists

To reap the maximum benefits, however, you should keep in mind that domain warm-up is an ongoing process. You must keep warming up your email domain over the months and years, to maintain your sender reputation at an acceptable level.

If done well, this will generate incredible ROI for your business, by enabling more effective lead generation and better communication with prospective clients and customers.

Other Articles You May Find Helpful:

  1.  A guide to using Snovio for your cold email outreach 
  2.  3 Battle Tested Strategies for Cold EMailing A Client
  3. The Best Cold Email Follow Up Sequence After No Response
  4. How To Maximize Your Cold Email Deliverability In 2022
Philip Ilic

Philip Ilic

B2B Growth Specialist

Phil helps B2B SaaS companies with growth marketing and is a deep specialist in Linkedin advertising and paid social more generally (Facebook, Twitter, LinkedIn). He runs a paid social agency called and is the founder of


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