According to statistics, 46% of emails landed in spam in 2022. And the reason is more than just impersonal subject lines and email content. 

The issue is sender reputation. 

Email providers consider “previous engagement’ a serious factor in sender reputation. A new email domain with little to no activity (no reply rates) is more likely to land in junk, promotions, or update folders than the “primary inbox”. 

This is where email warm-up enters to save the day.

If you don't want get into technical mumbo-jumbo, warm up using an AI-based automation tool. The AI will do everything for you—starting from sending emails to getting 30% reply rate. 

For instance, Smartlead’s unique algorithm has a human-like sending behavior. It gradually increases the number of sent emails, therefore, consistently improving your sender reputation.

Amazing, huh? Keep reading!

This article is all about warming-up an email address, its benefits, and how to do it.

What is Email Warm-Up?

Marketers send small numbers of emails (with or without using a tool) from a new sender’s address to build a good reputation with ESPs before sending out bulk emails. This process is called email warm-up. The goal is to avoid spam filters by starting small. 

When should you warm up email address

You should warm up an email before starting an email campaign or sending mass emails for any purpose at all.  

If you want to use a new sender’s address for cold email campaigns, warm it up for 2 weeks. 

You should warm-up an email for a minimum of 2 weeks. Start with as small as 40 marketing emails per mail address. 

If you have just begun your business with a new domain, take at least a month to begin outbound campaigns. It’s essential to build a domain reputation. And the ideal warm-up period before starting cold emailing is 2 to 3 months. 

Benefits of Warming Up Email Domain

Want to know how warming-up emails can benefit you? Here are some of its benefits.

Avoid Spam Filters/Folders

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If you send a huge volume of emails from a new email address without any cold email warm up process, you might end up being marked as spam by ESPs (Email Service Providers) such as Gmail, Outlook. 

As a result, your emails will automatically go to recipients' spam folders or get blocked entirely, eventually making the whole campaign useless. The best way to avoid this is to warm the address before starting your campaigns. It’s a proven way of reducing spam rates. 

Build Reputation

The warmup process helps to build your sender reputation. How?

Instead of sending bulk messages at once, it gradually increases the volume of emails sent and also the frequency. This tells the ESPs that you are not another “Nigerian Prince” spamming the users’ inboxes. 

You are a legitimate domain, and your messages are trustworthy. 

If you are entirely new to cold emailing, begin by sending a small volume of emails to your existing customers. You can even send it to your friends and family.

Improve Email Deliverability

If you build a reputation with the email providers before starting a cold outreach, it’s more likely that your emails will land in the primary inbox. 

This is because email providers will begin to recognize your sender address and reputation and will prioritize you over those from unknown senders.

Provides Time for A/B Testing 

A warm-up process is all about sending a few testing mails. Let’s say you are planning to launch a cold email campaign to promote a new product or service. So, you will begin by sending a small volume of emails to your most engaged subscribers and gradually increase the volume and frequency over a period of weeks. 

This allows you to test different content and subject lines and send times before launching a full-scale campaign to see what resonates best with your audience. By the time you launch your full-scale campaign, you have a higher chance of your emails being delivered to your intended recipients' inboxes.

Dear fellow marketers, it’s a great opportunity to do A/B testing. This can help to optimize your approach and increase customer engagement rates. 

Check out this article to read more about A/B testing.

Did Google Ban Email Warm-Up 

Yes, Google banned any automated email warming service. 

It wasn’t always like this. Email marketers throughout the industry used various cold email warm up tools like Gmass and Woodpecker to warm up senders' addresses. But, Google banned this feature in February 2023. 

Why did Google do that? 

Google considers this trick—warming up—as an “attempt” to bypass Gmail account limitations, spam filters, and other restrictions. In simpler words, they consider it a VIOLATION OF THEIR USER DATA POLICY. 

This BAN means you can’t use any AI-based automated email warmup tool for Google accounts. But does it mean you don’t warm up email accounts at all?

Nope. To learn how to warm up email accounts despite Google’s ban, read the next section.

How to Warm Up Emails Despite Google Ban

Like almost everything in the world, there are two ways of warming up an email account. 

1. Manually 
2. Automated

Manually, as you have already guessed, you will be gathering contacts, writing email content, and sending them all by yourself. 

In automated warm-ups, you will need to subscribe to a cold emailing tool with this feature. The AI will do all the work on your behalf of you. In 2023, it’s the most recommended way of warming up before a campaign. 

How to warm up email domain manually

Make an Email List

First things first, create an email list. As this is a manual process, you are going to do it by yourself. 

Make a list of mail addresses that might be willing to help you out. The list can contain your ex-co-workers, subordinates, business partners, friends, and even family. 

If you are active on LinkedIn, you can even ask a few of your connections to help you out. Try to include as many business owners as you can. Their addresses are mostly with their domain names, such as vaibhav@smartlead.ai. 

The more unique the domain name is, the better. 

Segment Email List

Now, keep all the business owners and decision-makers in a section. Keep your personal contacts—friends and family—in one section. And make another section/list for your existing customers. 

Set Mail Exchange Record

MX record or the mail exchange record is a resource record in the DNS (Domain Name System). It says that the emails should be redirected to a specified mail server that accepts emails on behalf of a domain or users. 

You can set routing priorities (which mail server will be used) within an MX record by using preference if there are multiple servers. Before beginning with any kind of mailing from a new domain, it's important to set this up. 

Go for SPF, DKIM, and DMARC authentication

This step is crucial for a new sender’s address. It will provide protection from spam filters. 

SPF, or Sender Policy Framework, is an email authentication method. It creates a record of all the authorized email servers in your DNS (Domain Name System). These servers send mails on your domain’s behalf and authenticate it.

DKIM or Domain Keys Identified Mail adds a digital signature to your domain and DMARC provides domain-level protection. 

DMARC stands for Domain-based Message Authentication, Reporting & Conformance. 

Create Email Content

You are a genuine marketer (a human), so create content that wouldn’t sound like spam or robots. Here’s a checklist for you to sound like real people (as you are):

• Cleartcut subject line 
• No spammy words 
• Write proper text
• Value-adding content
• Email body in less than 150 words
• Add a proportionate email signature
• Attach value-adding content only

Write the content that you can envision your recipients opening. If you are confused, you can do manual A/B testing.  

Just create two versions of the same email and send it to two different groups of recipients. Compare the results to see which one performed better. 

Send 20 Mails/Day

You are doing it by yourself, so do not send more than 20 emails per day as per gmail email limit. Use different segments of your contacts to do that. 

Continue this process for at least 14 days before increasing the number of mails. From 20, increase it to 50, and then 100, and so on. 

Optimize Send Time

Don’t send all the mails at once. Divide them into smaller batches, even if you are sending the same content. 

You can customize the send time. This feature is available on almost all platforms. So, don’t forget to send messages at different times. 

Create Email Threads

Ask your closest contacts to respond to your emails. If possible, then forward them as well. 

Try to continue the conversation and create email threads. 

Ask to Whitelist

Ask your recipients to add your new mail address to their contact list. This tells their email client that they know you, the sender, and they want to keep receiving your mails. 

This process is called whitelisting. Request your known contacts, family, and friends to whitelist your new address during the warming-up period. 

Subscribe to Receive Mails

To warm up an address, receiving emails is as important as sending emails. It’s always better if you can subscribe to emails from known brands. 

You can also subscribe to newsletters. Receiving emails regularly shows that you are a genuine user. The goal is to validate your existence as an email user. 

How to do automated email warm-up

You will need an AI-based cold emailing tool to automate warm-ups. Let me take you through how to warm up an email with Smartlead.

FYI, Smartlead “manually” moves emails landed in spam to the primary inbox, marks them as important.

Let's get started. ‍

Set up your account

Sign in to the Smartlead app and click on the “Email Accounts” tab. 

Next, click on the “Add Account” box on the top right of the page. 

On clicking on “Add account” there will be a pop-up box on your screen.

You can click on Gmail, SMTP, Outlook, or Zoho based on the email address you want to use. Click on this link for technical assistance on setting up your email account. 

Do the SPF, DKIM, DMARC & MX Set Up

SPF - Sender Policy Framework

DKIM - Domain Keys Identified Mail  

DMARC - Domain-based Message Authentication, Reporting & Conformance. 

MX - Mail Exchange Record

Next, complete these set-ups before starting the automated warm-up process. If you are using Smartlead, checkout this article for this step.

Select the Email You Want to Warm Up

Once you are done with the SPF, DKIM, DMARC & MX set up, open the Smartlead app (or whichever app you are using). 

Go to the “Email Accounts” tab. Select the email account you want to enable warm up for. 

Fill the Configuration Settings

Fill in the details, as shown on the below page. 

Keep this things in mind while filling up the configuration settings:

👉Total number of warm-up emails per day shouldn’t be more than 40

👉 If you are using a new domain, turn “Daily Rampup”. It will naturally progress the number of emails you send each day, instead of jumpscaring ESPs with bulk messages. This prevents Email Service Provides (Gmail, Zoho etc…) from flagging your account for unusual activity.

👉 To look more human, randomize the number of emails sent everyday. 

👉 Set the reply rate between 30-40% to boost deliverability and reputation. 

👉 The Custom Warmup Identifier Tag helps to filter out any warm up emails from your inbox.

Click on “Save/Update”

Once you are done with this, click on “save” on the bottom right and you are done. If you have warmed up the email in the past, it will show an “update” option.

Track Performance

Now, you can sit back and relax. Keep a track of the warming-up process from the Smartlead (or whatever app you are using) dashboard. 

This was the process of automating email warming up process. Looks easy, right? It's effective too.

10 DOs & DON’Ts of Email Warm-Up

Now that you know what is email warmup, why should you do it, and how to do it; it’s time to summarize all the points in one section.

I have listed down all the necessary points. Take a look at the (below) DOs & DON’Ts of the email warm-up. 

DOs

First, let me tell you what you must do while warming up a mail address. 

• Start with a small email list and gradually increase the number of recipients over time.
• Send a consistent volume of emails every day to avoid sudden spikes in sending activity.
• Use a reputable email service provider that is well-suited for email warm-up.
• Personalize your mails, by including the recipient's name or other relevant information.
• Keep your email content relevant and engaging to encourage your prospects to open and engage with your mails.
• Monitor your email performance metrics (e.g., open rates, click-through rates) to track your progress.
• Gradually increase the frequency of your mails over time, as your email reputation improves.
• Keep a clean email list by removing inactive subscribers and hard bounces regularly.
• Segment your email list based on recipient behavior or characteristics to send more targeted mails.
• Engage with your subscribers in other ways, such as through social media or blog posts, to build trust and credibility.

DON'Ts

Here’s a list of points you must keep in mind while warming up. Make sure you NEVER do these. 

• DON'T buy email lists or use any other shady tactics to acquire email addresses.
• DON'T send mails with large attachments, as this can trigger spam filters.
• DON'T send mails with a high image-to-text ratio, as this can also trigger spam filters.
• DON'T send mails with excessive punctuation or capitalization, as this can make your mails look like spam emails.
• DON'T send mails with deceptive subject lines or misleading content.
• DON'T exceed the planned daily send volume
• DON'T send mails to unengaged subscribers or inactive accounts, as this can lead to a bad reputation.
• DON'T use too many links in your mails, as this can trigger spam filters.
• DON'T use too many images in your mails, as this can also make your emails look spammy.
• DON'T use generic (too formal) language in your emails, as this can reduce engagement and trust.

Email Warmup Best Practices

Warming up your email account is an essential step to ensure your cold email campaigns have high deliverability rates. Here are some best practices to follow for effective email warmup:

1. Start Slowly: Begin by sending a small number of emails daily and gradually increase the volume over time. This gradual approach mimics natural email activity, helping to build a positive sender reputation. For example, start with 10-20 emails per day and increase by 10-20 each week until you reach your desired volume.
2. Engage with Warm Contacts: Initially, send emails to contacts who are likely to open and engage with your messages. This could be colleagues, friends, or existing customers. High engagement rates signal to email service providers (ESPs) that your emails are valuable, improving your sender's reputation.
3. Use an Email Warmup Tool: Leveraging tools like Smartlead, Mailshake, and Lemlist can automate the process and provide analytics to track your progress. These email warmup services simulate real email activity by engaging with the emails you send, opening them, marking them as important, and replying to them.
4. Diversify Content: When warming up your email, vary your content to include a mix of text and images, and avoid repetitive messages. This diversity helps ESPs recognize your emails as legitimate communication rather than spam.
5. Monitor Domain Health: Regularly check your domain's health using tools like Google Postmaster Tools and Smartlead's Domain/IP Checker. These tools provide insights into your sender reputation, spam rates, and other critical metrics, allowing you to make adjustments as needed.
6. Authenticate Your Emails: Ensure that your email authentication protocols like SPF, DKIM, and DMARC are correctly configured. These protocols help ESPs verify the authenticity of your emails, reducing the likelihood of your messages being marked as spam.
7. Consistent Sending Schedule: Maintain a consistent sending schedule to build trust with ESPs. Avoid sudden spikes in email volume, as this can trigger spam filters. A steady increase in volume over weeks or months is more effective.

By following these best practices, you can successfully warm up your email account, ensuring higher deliverability rates and a stronger foundation for your cold email campaigns.

Common Pitfalls to Avoid When Warming Up Emails

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While warming up your email account is crucial for successful cold email outreach, several common pitfalls can hinder your efforts. Here are key mistakes to avoid:

1. Sending Too Many Emails Too Soon: One of the biggest mistakes is ramping up your email volume too quickly. ESPs are likely to flag this sudden spike as suspicious activity, which can harm your sender's reputation and lead to your emails being marked as spam. Patience and gradual scaling are fundamental to a successful email warmup.
2. Ignoring Engagement Rates: Failing to track and respond to engagement metrics can derail your warmup process. Low open and engagement rates are red flags for ESPs. Focus on sending emails to recipients who are likely to engage positively. Use tools for inbox warming that monitor and improve engagement automatically.
3. Using Unverified Email Lists: Sending emails to unverified or outdated lists can result in high bounce rates, negatively impacting your sender's reputation. Always verify your email list before starting the warmup process using email verification tools to ensure you're contacting valid addresses.
4. Lack of Authentication: Not setting up proper email authentication (SPF, DKIM, DMARC) can lead to poor deliverability and your emails being marked as fraudulent. Ensure these protocols are correctly configured to authenticate your sending domain.
5. Repeating Content: Using repetitive or identical content in your warmup emails can trigger spam filters. Diversify your email content to include different subjects, body texts, and formats. This variation helps ESPs identify your emails as legitimate communications.
6. Neglecting Domain Health: Regularly monitoring your domain health is essential. Using tools like Smartlead's Domain/IP Checker can provide insights into your sender reputation, spam rates, and other vital metrics. Ignoring these can lead to issues that might affect your overall email deliverability.
7. Inconsistent Sending Patterns: Erratic or inconsistent sending patterns can cause suspicion among ESPs. Establish a consistent sending schedule and stick to it, gradually increasing your email volume over time to build a solid sender reputation.

Before sending out bulk emails, it's essential to ensure that your email address has built a solid reputation. Smartlead offers you advanced email warmup capabilities that give you more control over the warmup process, improving deliverability and enhancing engagement.

By avoiding these common pitfalls, you can effectively warm up your email account, ensuring better deliverability and engagement rates for your cold email campaigns.

Whether you're looking to warm up a Gmail account or use a mail warmer, following these guidelines will set you on the path to success.‍

Advanced Warmup Features: Enhance Your Email Reputation

Smartlead’s warmup approach follows a set of principles designed to optimize deliverability:

1. Outbound (Going Out): Sends emails to build activity from your domain.
2. Outbound-Reply (Coming In): Ensures responses to your emails, which signal to ESPs that you're engaging in real conversations.
3. Inbound (Coming In): Helps manage inbound replies and ensures your domain continues to maintain a good reputation.
4. Inbound-Reply (Going Out): Human-like responses to inbound emails improve the sender’s reputation, ensuring higher engagement and trust.

What’s New in Smartlead’s Warmup Features?

• Dynamic Inbound-Reply Control: You now have the ability to decide how many inbound emails you want to reply to, with an advanced algorithm that mimics real human behavior, keeping your domain’s reputation intact.
• Faster Bounce Rate Control: Our system reduces bounce rates quickly, cleaning up your email pool proactively and reactively, making sure your emails don’t get flagged.
• Manual Verification for Quality Control: With over 25,000 professional mailboxes, we're manually verifying each mailbox to improve warmup quality, dropping the bounce rate to as low as 0.1%.

The Result?

• Improved deliverability rates.
• Increased reply rates.
• Reduced spam placement.

By incorporating these advanced features into your email warmup strategy, you’ll be able to ensure that your cold email campaigns land in the primary inbox, driving predictable results.

Final Thoughts!

Google banned email warm-ups for Gmail users but does it mean it’s the end of this process?

No, it’s not. Warming up was and still is a crucial process before launching an outreach campaign. For Gmail users, you can warm up manually. It’s a time taking process, I know. But if you send messages to only a handful of contacts, then you can do it. 

Other than that, automated warming-up is the best way to do it. You can gradually increase the volume–from 40 mails per day to 1000 mails/per day. All it needs is to configure the warm-up setting. 

If you are new to cold email marketing, then learn to structure a cold email. Go through this process. It will bring amazing results from your upcoming outreach campaigns.

FAQs

How do I manually warm up an email?

You can manually warm up an email address by sending fifteen to twenty messages every day. Send value-adding content to an active mail list. 

Keep doing this for five to six days then gradually increase the number of sent mails. Ask your contacts to write back to you on the same thread. This will pace up the warming up. 

Also, don’t use the same contacts to send mails every day. Use new contacts, please. 

What is the fastest way to warm up an email domain?

There is no fastest way to warm up a domain. Take at least a month to begin your outreach campaigns full-fledged. If you are adding a new address to your domain, then take fourteen to twenty days to warm it up. 

The fastest way to do this is obviously by using an automated warming-up tool. But you can’t do that for Gmail users. For Gmail accounts, the only way is to send a handful of emails to people you know–manually. 

How long does it typically take to warm up an email address?

It takes at least 2 weeks of warming email with gradual increasing numbers of sent emails. Start with 40 emails per email account and gradually ramp up the sending volume.

Is there a difference between warming up an individual email address and an entire email domain?

Warming up an email account and warming up a domain are pretty much the same and follow the same steps. However, if you are using a newly-created domain, it will take longer than an warming up an individual email account.

What are the consequences of not warming up an email or domain properly?

Your domain reputation will get hampered and eventually a large number of your emails will either bounce back or land in the spam folders.

How often should I send emails during the warm-up process?

To help ensure a human-like email sending pattern, Smartlead recommends 8 minutes gap between sending emails.

Can I speed up the email warming process?

You can speed up the warming email process, but it's not advisable, as ISPs monitor your email activity all the time and you may get flagged as spam when you launch email campaigns.