What Happens When You Don’t Warm Up Your Emails

A smart email warmup strategy ensures your messages land in inboxes instead of spam folders. But what happens if you decide to skip warming up?

With 93% of people using email every day, virtually nobody disagrees that email is how you reach people. But if your IP address and domain don’t have a good reputation with email providers, your emails may not actually make it to the inbox. 

So how do you change that? 

Warming up your emails and having a solid email warmup strategy in place can make all the difference in reaching your customers. On the other hand, not warming up emails can have disastrous consequences on your sender reputation and email deliverability.

Here’s what happens when you don’t warm up your emails properly – and what to do instead.

Why you need an email warmup strategy

Email warmup is a process for progressively increasing the number of emails you send from a new, inactive or damaged email account to develop your sender reputation. 

Think of it as introducing yourself to email service providers (ESPs) and showing them you’re a legitimate sender. Believe it or not, spammers outnumber legitimate email senders like you, which is why this process is so important. Warming up your emails shows you are not like them.

ESPs use sophisticated algorithms to decide if an email should go to the inbox, the spam folder, or be blocked entirely. If you skip the warmup process and start blasting out emails, your sender reputation takes a hit, and your messages will likely be discarded before they even reach your audience. 

The consequences? 

Poor deliverability, fewer opens, and a lot of wasted effort. It’s better to warm up your emails than to scramble around doing damage control.

If you are experiencing any of the following, it could be because of warmup related problems. Here are the most common signs your IP and domain have a reputation issue – and how to fix it.

1. Warm up, or your emails may go straight to spam

If you start sending a high volume of emails without warming up your account, ESPs will see it as suspicious activity. They track the reputation of all senders, and a sudden surge in email traffic from an untrusted source inevitably raises red flags. 

When ESPs aren’t sure if you’re a legitimate sender, they understandably play it safe by diverting your emails into the spam folder. And let’s be real: once an email lands in spam, it’s pretty much out of sight, out of mind. Your open rates plummet, and engagement drops because people simply aren’t seeing your messages.

2. Your domain reputation suffers

Your email-sending reputation works a lot like a credit score. Sending too many emails too fast without warming up is like exceeding your credit limit; only ESPs don’t provide any notices in the mail.

ESPs and ISPs (Internet Service Providers) keep track of how reliable your domain is, and if they notice reckless sending behavior, your credibility takes a hit. A damaged sender reputation makes getting your emails into inboxes even harder, creating a downward spiral. 

And once your reputation is in poor shape, fixing it takes a lot of time and maneuver — you’ll have to send smaller batches, improve engagement, and prove you’re not a spammer. It’s better to have an email warmup strategy and avoid dings on your domain reputation.

Related: Top reasons your emails are flagged as spam

3. Your emails get less engagement

Even if your emails don’t go directly to spam, if you failing to warm up emails properly means they’re more likely to get pushed to the promotions tab or deprioritized by ESPs. And if your emails aren’t front and center, fewer people will open them. 

Low open rates tell ESPs that your emails aren’t valued, which makes it even more challenging to land in inboxes in the future. It’s a vicious cycle:

• Poor deliverability leads to low engagement 
• Low engagement further hurts your deliverability. 

Without an email warmup plan, your campaigns might never get the visibility needed to succeed.

4. You may get higher bounce rates

Sending cold emails without warming up your IP and domain can lead to an increased bounce rate. A bounced email is one that couldn’t be delivered, often because the email address doesn’t exist or isn’t active anymore. 

ESPs and ISPs track bounce rates, and if too many of your emails bounce, they assume you’re not maintaining a clean email list or that you’re sending spam. A high bounce rate damages your sender reputation and increases the chances of your future emails getting blocked.

5. ISPs eventually block your emails altogether

If your sending behavior raises suspicions — whether it’s a sudden spike in volume, high bounce rates, or low engagement — ISPs may take more drastic action. They have automated systems that monitor for potential spammers, and if you trigger too many red flags, your emails might be blocked entirely. 

Getting blacklisted is, bar none, one of the worst things that can happen to your email campaigns because once you’re on a blacklist, your emails won’t reach people, no matter how good your content is. 

And how do you go about getting removed from a blacklist? That can be a long, tedious process that requires first getting some knowledge about making amends, then proving you’ve changed your sending habits so you can gain the trust of ESPs.

How to properly warm up your emails

The good news? All of these problems are avoidable if you take the time to warm up your emails properly. There’s two ways to achieve this. 

There’s a more advanced, laborious way that takes quite a bit of diligence and care.
Here’s what to do if you take this approach:

• Start slow – Gradually increase your email volume instead of sending a massive batch all at once. Begin with a small number of emails and work your way up over time. Find sending limits for major ESPs in our Email Deliverability Guide and build your email warmup strategy around these limits.
• Send to engaged recipients first – Start by emailing people who are most likely to open, read, and interact with your emails. High engagement early on helps build a good sender reputation.
• Monitor key metrics – Keep an eye on your open rates, bounce rates, and spam complaints. If you notice any red flags, adjust your strategy before things get worse.

The downside is that this email warmup method is tedious and prone to human errors. There is an easier, more effective, and rigorous method which we will go into next. 

Use email warmup tools for the best results

Email warmup tools help you build a higher sender reputation by steadily increasing your email volume and automating every step of the process. 

Instead of immediately sending a high number of emails —which would trigger spam filters — a good email warm-up tool will ease you into an ideal sending pattern, which greatly improves your chances of landing in inboxes.

To get the best results, choosing a tool that’s dialed into accuracy and consistency is key. How you configure the tool to work for you is equally important.  

Here’s what to keep in mind:

• Make sure the information you input, like your usual email volume, is correct so the tool can mimic natural sending behavior. 
• Keep your warmup period steady for at least 30 days, and avoid sudden changes in how many emails you send. This keeps your engagement looking organic and trustworthy.
• Be patient. A proper email warmup strategy takes time, usually three to six months, to establish your credibility. Rushing this process makes your emails look suspicious to inbox providers. A slow and steady approach ensures your emails get delivered and opened, so you can connect with your audience the right way.

Slow and steady wins the email race

If you remember one thing, let it be this: people warm up before exercise or sports to avoid injury. Warming up your emails prevents injury to your email deliverability.

Skipping the email warmup process might seem like a shortcut, but in reality, it delays your success. Jumping right into cold emailing will always do more harm than good. Without warming up your IP and domain, your emails are more likely to go to spam, your domain reputation will suffer, and your engagement will take a nosedive. 

Worst case scenario? Your emails could be blocked entirely, cutting off your primary communication method with your audience. But with a proper email warmup strategy, you establish trust with ESPs, improve your deliverability, and greatly increase your chances of success. So, take the time to warm up your emails — your email performance counts on it.