Did you register a brand new email domain, yet your emails are ending up in the spam folders?
Well … you probably forgot to warm up it first.
Having a properly warmed-up email domain is a necessary step even when it is a completely new one, without any bad reputation.
In this article, we will therefore take a look at what domain warm up is exactly, how it works as well as how to do it properly.
Domain warm-up is a process of sending emails from a new (or cold) email domain and gradually increasing send volumes in order to establish a positive email reputation.
The purpose of domain warm-up is to improve your domain reputation and gain ESPs’ trust so all your emails can be delivered right into recipients’ inboxes (and not be blocked by spam filters).
Whenever you start sending emails from a completely new email domain with zero reputation, ISPs and ESPs (Email Service Providers) can get suspicious about it and prevent your domain from delivering a larger number of messages at once until you “prove” that you are a reliable email sender.
Once ISPs have some historical data about your domain and your email activity, they will allow you to send more messages to a larger audience – or vice versa, throttle your email volumes if you start to have a bad domain reputation.
Domain warmup helps to create a positive email reputation for your new domain by gradually sending a larger and larger number of messages over several weeks until your domain is ready and properly “warmed up”.
Note: It is important to understand that domain reputation is not the only factor that can impact your email deliverability.
ISPs and ESPs also take into consideration the reputation of your IP address, subdomains, or even a specific email address when determining if or how many messages should be delivered to your recipients.
A domain’s reputation can be influenced by many factors such as:
It’s important, though, to understand that not all of these components carry the same weight.
For example, if some people unsubscribe from your email list, the domain reputation won’t change that much – on the other hand, having many spam reports can severely damage the reputation of your domain.
Domain warmup involves a lot of activities that can slowly (but surely) improve your domain reputation over time.
Here are a few practices that you should keep in mind when warming up your email domains:
Depending on the number of emails you want to send per day, you may want to look into upgrading your ESP.
We do not recommend sending email blasts from a free Gmail or Outlook account because scammers tend to use these and you will be flagged.
It’s also important to understand that many ESPs equate the “number of emails sent” with the “number of recipients.” In short, trying to circumvent the limits by BCC-ing all of your recipients on a single message won’t work.
Here’s a quick list of some of the most popular ESPs and their sending limits.
Email Service Provider Sending Limit (Per Day)
Gmail (Free) 500
Gmail (Google Workspace) 2000
Outlook (Free) 300
Microsoft 365/Office 365 10000
Zoho (Free) 50
Zoho (Paid) 300
Zoho (Custom) 2500
GoDaddy 250
RackSpace 10000
Yahoo! 500
BlueHost 150 (per hour)
DreamHost 100 (per hour)
Yandex.mail 500
HostGator 12000
Amazon SES 10000
Proton Mail (Free) 150
Proton Mail (Plus) 1000
Proton Mail (Professional/Visionary) unlimited
AOL 500
Mailgun 300
SendGrid (Free) 100
SendGrid (Essentials) Up to 100,000 per month
SendGrid (Pro) Up to 1.5 million per month
Sendpost (Starter) 10,000 per month
Sendpost (Growth) 600,000 per month
Sendpost (Scale) 3 million per month
Email authentication can indicate to ISPs that your domain is reliable and can be trusted.
Authentication allows receiving servers to quickly verify your emails and prevent hackers from spoofing your account.
It also shows that you prioritize your customers’ well-being and don’t want them to be flooded with spammy messages.
The email authentication consists of 3 parts (and it’s best to take the time to complete all of them):
Having a positive IP reputation is as equally important as having a good domain one.
If your IP address gets a bad rep, all of your emails will be either blocked or simply end up in the spam folder – and your domain reputation will suffer along the way too.
ISPs are doing everything they can to protect their users from spam and malicious content, so if you have a less-than-stellar IP reputation, your emails might not get delivered to your subscribers.
Spam filters are sensitive to the content that your emails contain, especially for risky words that just attract attention and mislead the readers.
Due to this fact, try to avoid words like “FREE”, “75% OFF”, “BUY RIGHT NOW”, etc., since it will just increase the chance that your emails will end up in spam folders.
The same can be applied to click-bait titles or claims in your emails that are promising some prize but in reality leading to something completely different.
Writing a good and relevant email copy does not probably need an explanation – if your email content seems like a scam, recipients won’t click on any of your promotion links (and probably won’t open your messages in the future ever again).
At the end of the day, with scammy content, you will probably get a lot of spam reports – which will hurt your domain warm-up process as well as your domain reputation overall.
Although creating a good email copy is a little bit of an art and requires some marketing skills, there are a few ways how you can improve your email content immediately:
Creating positive engagement and getting responses is a huge plus for your domain reputation – but that is just half of the work.
When getting answers to your messages, try to keep up the conversations flowing and reply to users who wrote you back.
Having regular conversations is a strong signal for email service providers that your email account is trustworthy – which leads to a quicker warmup of your email domain.
Regular cleaning of your email lists will help you save your resources as well as keep your open rates and CTRs high (since you will be keeping only email addresses that are used by real people).
Cleaning your email lists can also help you get rid of the users who simply are not interested in your content anymore (and probably won’t read your emails even after 5 or 10 email campaigns).
To get rid of invalid email addresses, spam traps, or soft bounces, you need to use tools like EmailListVerify that can automatically “catch” and delete these types of addresses for you.
Regular checking and cleaning of your email lists can help you to:
If you’re operating on a shared IP, you may want to consider transferring your information to a dedicated IP to have more control over your reputation.
Shared IP and its reputation can be negatively impacted by other people who are using it as well – even if you would try your best to properly warm up the IP address, the IP reputation could be easily damaged by spammers or scammers who would use the given IP for their malicious email activities.
Switching to a dedicated IP address will help you to solve this issue and give you full control over its reputation (+ domain reputation as well).
Warming up a new email domain is a pretty straightforward process but also very time-consuming: you have to prepare engaging content, keep up with conversations, and continuously send more and more emails over a long period of time.
That is why it is always a good idea to use tools that are capable of warming up inboxes for you, such as our Warmup tool.
Warmup Inbox is a pretty easy and straightforward tool – it sends out emails on your behalf, gets responses, creates engagement in email threads, etc. within our platform.
It contains hundreds of other email accounts that automatically communicate with each other.
Once your email account is synced with Warmup Inbox, there are a number of ways that our tool can help automate the process of building up your email reputation: