The guide to email warmup in 2024
Lead Generation

The guide to email warmup in 2024

Everything you need to know about warming up your email addresses and always landing in the primary inbox

What is email warmup? 

Once you have your email account created, you still have to prepare it for outbound. This is done through email warmup. 

Email warmup is simply the process of improving your sender reputation by sending and responding to emails. This is done by gradually ramping up your volume until your email account is considered safe enough for cold outbound. There are several tools that exist today to help you with this process, some of which have adapted very well to email deliverability in 2024.

Warming up your email used to mean sending a few emails to your friends and getting them to respond before launching a campaign. Today, warming up your email account consists of joining an email network that will automatically send and receive emails from your account. This is done long enough so that spam filters and email service providers begin to trust your email address and domain before you begin outreach.

Why you need email warmup

1. Improving your sender reputation

A newly-created email account is a prime target for spam filters. At that point, you have no credibility yet (for your email address or domain) as a valid sender. Every email you send goes through additional scrutiny as this will be the foundation for your sending reputation. 

Using a warmup service will lead to lots of responses to your warmup emails. The reality is that most outbound campaigns have low engagement.

In many cases, that spells trouble as email service providers are always monitoring the rate at which you are getting responses vs. spam complaints. Warming up your email address allows you to get the responses you need to build up your credibility.

2. Monitoring your sender reputation

Do you ever wish you knew if you were landing in spam or not? An email warmup tool will let you know exactly how many of your warmup emails are landing in spam, and which email service providers they are in spam for (Outlook, Gmaill, etc.). 

This is a much better way to guage outbound performance then using open rates. Open rates today aren’t even accurate anymore. And if they do work, they are a lagging indicator for the real issues behind your deliverability that your warmup data can identify.

This is one of the reasons it’s important to keep running your email warmup once you start sending outbound emails.

3. Repairing your sender reputation

You never want to get this message about one of your accounts, but this happens to sales teams all the time when they don’t cover the fundamentals of today’s best practices for sales outreach. 

It’s easy to get the account recovered - the challenge is in fixing your sending reputation. Every email you send from an account after it’s been suspended is at risk. 

There is a worse scenario - your warmup data shows all of your emails from a specific address are landing in spam. 

Having an email warmup tool is helpful here because you can stop the damage before your open rates tank and your domain is irreversibly damaged. At this point, you need to stop all outbound activity immediately from this address and begin the recovery process to get out of spam trouble.

4. Warmup criteria

There are several parts of email warmup that you want to be sure your warmup tool has. 

  1. A large network of real inboxes

Your warmup tool needs to have enough inboxes to:

  • Give you enough variety in your senders’ list
  • Be able to easily swap out damaged inboxes
  • Have a high enough reputation and be more realistic
  1. a legitimate email sender

If your warmup tool runs into deliverability trouble, all your emails are in trouble - both your warmup and non-warmup emails. New tools without a history of proven delivearbility are too risky.

  1. realistic messaging

The AI used in spam detection tools get better every year. You can’t use the same unrealistic email templates that warmup tools used to put out in 2019. 

This is a good warmup email. Personalized, realistic, and free of any keywords that will automatically land you in spam. 

  1. Control over your variables

Depending on your situation, you need to be able to adjust your open rates, reply rates, warmup ramp time and daily limits

This also includes advanced control like the ability to mark emails as important and remove them from spam.

These are the nine best warmup tools on the market today.

5. Warmup schedule

As you already know, you have to warmup your email addresses before they’re ready for cold emails. How long should you wait?

If you’re using Gmail or Outlook servers, it’s recommended to warm your emails up for 2-3 weeks before sending any outbound. Once you do start sending emails it’s important that you ramp them up slowly before reaching full capacity (one of our 10 rules for avoiding spam trouble). We use custom-built servers at Zevenue which keep our warmup time to just 10 days.

6. Newsletters

Here’s a bonus deliverability trick - you can sign up for email newsletters to make your email address appear to be that much more reliable. Think of this like using backlinks but for your inbox rather than your website. This is our step-by-step guide on how to make this as realistic as possible.

7. Manual vs automatic

You could also do this manually, with much more of a challenge. You would need:

  • Access to several email addresses on domains that have been reliable for over a year
  • Access to email addresses on Google Workspace and Microsoft Outlook, not just personal accounts
  • Time to send and respond to these emails
  • Extra attention to pull emails out of spam when they land there and mark them as important

With all of this in hand, you can gradually ramp up your volume each day for two weeks, or longer if you notice any emails landing in spam. 

In most cases, it just isn’t worth it to go through this hassle manually. Warmup tools have come down in cost enough to the point that it’s nearly a no-brainer to use them instead. 


IEmail warmup is essential for successful outbound campaigns and avoiding spam nowadays. The only way to build real address and domain reputation is by gradually ramping up email volume and engaging with responses. This doesn't stop once your campaign begins - monitoring warmup emails gives you insights on campaign performance and helps you fix things when you make mistakes. Most warmup tools are cost-efficient and worth the results they bring to your sales motion.

We help founders and sales leaders solve this by handling your entire outbound motion. Zevenue writes your campaigns, manages your sending infrastructure, and handles all your lead list building and troubleshooting to give you differentiated, unique campaigns that lead to real sales pipeline. If you’re working on this right now, let us know what questions you have. Send us a message and we’d be glad to help!

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