8 Free Email Spam Checkers You Can Use To Land In Inboxes

Ever poured your time and efforts into a cold email… only for it to end up in the spam folder?

Yeah, it is frustrating. 😩

You spend time writing the perfect message, personalizing it, and hitting send—only to realize your prospect never saw it. 

That’s where spam checkers come in handy.

In this blog, I’ll share the top 8 free email spam checkers you can use to find out whether your emails will land in your prospect’s inbox—or get stuck in the spam folder.

Let’s get started! 

What is an Email Spam Checker?

An email spam checker is a tool that helps you evaluate all aspects of your email deliverability, including the subject line, content, sender reputation, and technical configurations (like SPF, DKIM, and DMARC records).

Simply put, it estimates whether your email will reach the recipient’s inbox or get flagged by spam filters.

TL;DR: Which FREE Email Spam Checker Tool is the Best?

If you’re in a hurry and need to immediately check whether your email will land in the spam box or inbox, here are the top 3 free email spam checker tools you can try:

• GlockApps: All-in-one spam checker that gives highly accurate results
• MailGenius: Offers highly detailed spam reports along with a preview of your emails
• Unspam Email: Along with a spam score, Unspam email also shows you which part of your email will get the most attention from recipients

My List of Top 8 Free Email Spam Checkers

Finally, we get to my list of the best 8 safe and free email spam checker tools. 

As someone who has been sending cold emails for a long time, I’ve tried and tested a lot of different free email spam checkers. 

Out of all of them, I’ve selected the 8 best tools that have given me the most accurate results.

For every tool on the list, you’ll find its G2 rating, Pros & cons and User reviews.

Here are the 8 tools that I’ve selected after running spam checks with each and every one:

• GlockApps
• MxToolbox
• Google Postmaster
• Smartlead
• MailGenius
• MailTester
• Unspam Email
• Experte 

Let’s go through all the free spam checkers one by one:

1. GlockApps

G2 Rating: 3.7/5⭐

First on my list of the best free spam checkers is GlockApps. 

It’s a solid email deliverability tool that gives you 3 free spam tests every 24 hours—which is perfect if you’re just starting out or testing a few campaigns.

I’ve placed it at the top because it doesn’t just show you a spam score. It actually gives useful insights into your email content and domain health—so you can figure out what’s hurting your deliverability.

Here’s how it works:

• You get a custom email address from GlockApps
• Just send your email to that address
• And it’ll break down the spam score based on your content and setup      

Now let’s quickly go over some pros and cons.

Pros:

• GlockApps lets you test your email authentication records for free.
• Integrates seamlessly with Google’s Postmaster Tools.
• Offers actionable insights into how you can improve the deliverability of your emails.

Cons

• The customer support is poor.

What do Users Have to Say?

2. MXToolbox

G2 Rating: 4.1/5⭐

Next, we come to MxToolbox—one of my favorite free email spam checkers.

MxToolbox isn’t like most other spam checkers. While many tools focus on flagging spammy words in your email content, MxToolbox focuses on your email’s infrastructure.

This means it checks whether your authentication records are set up correctly and if your domain health is in good shape.

So, how can you use MxToolbox as a spam checker?

It’s simple: just enter your domain name into the text box on MxToolbox’s homepage. It’ll show you whether your domain is considered a trusted source for email delivery.

Another great feature is MX Complaints, which gives you actionable insights into spam complaints that email service providers (ESPs) are receiving about your emails. This can help you improve your inbox placement rate over time.

Here’s a quick look at its pros and cons:

Pros:

• Helps you test and verify your email authentication records.
• The Delivery Center offers real-time insights into your email deliverability.
• Comes with a Free Monitor that alerts you about email delivery issues.

Cons:

• MxToolbox’s spam check doesn’t cover your email’s content.

What do Users Have to Say?

Recommended Read: How to avoid spam filters?

3. Google Postmaster

G2 Rating: N/A

Google Postmaster Tools is a free tool by Google that helps email senders monitor their email performance when sending to Gmail users. 

It provides data on deliverability, spam rates, and domain reputation, helping you understand if your emails are reaching inboxes or getting flagged.   

Pros:

• Allows you to see your domain and IP reputation.
• Helps you identify if Gmail is marking your emails as spam.
• Shows if your emails are passing SPF, DKIM, and DMARC checks.
• You can track how Gmail treats your email campaigns over time.

Cons:

• It only works with Gmail data and provides no insights for other providers, such as Outlook or Yahoo.    

What do Users Have to Say?

N/A

4. Smartlead

G2 Rating: 4.6/5 ⭐

Out of all the free email spam checkers I tried, Smartlead’s was the easiest to use.

Just copy and paste your email, and it quickly checks how “spammy” it is- simple right! 

Unlike many other tools out there, Smartlead’s spam checker is completely free. No hidden limits or trial restrictions.

And it doesn’t stop there—along with spam checking, it also offers handy features like Email Authentication, Deliverability Tools, and Content Enhancement. 

So before you hit send, you can be confident your email is ready to land in your prospect’s inbox.

Pros

• It allows you to easily spot and fix spam trigger words before sending your email.  
• You get a clear report showing if your email will land in the inbox or spam folder.  
• You’ll find the tool easy to use, even if you’re new to cold emailing.

Cons:

• The results aren’t always accurate.

What do Users Have to Say?

Recommended Read: Smartlead Alternatives

5. MailGenius

G2 Rating: 4.5/5⭐

Next on my list of the best free spam checker tools is MailGenius, which works with every ESP.

Like GlockApps, MailGenius also lets you run 3 free spam tests per day.

One thing I like about MailGenius is that it provides a detailed spam score. The score is based on your authentication records, domain and sender reputation, and the content of your email.

Here’s how MailGenius stacks up as a free email spam checker platform:

Pros:

• Tells you whether your email content contains any known spam triggers.
• Ensures that your email address is not on any spam blacklists.
• You can integrate MailGenius directly into your cold email infrastructure.

Cons:

• MailGenius’ AI features can be overwhelming, especially if you want a simple spam-checking experience.

What do Users Have to Say? 

6. MailTester

G2 Rating: 4./5⭐

Last on my list of the top 8 free email spam checkers is MailTester.

It takes a slightly different approach to spam testing. You don’t have to send an email to a specific address to check if it would land in the spam folder.

Instead, MailTester helps you test your email infrastructure in two key ways:

First, it scans your email list for spam traps and helps eliminate them.
Second, it checks your email to see if it would be flagged as spam by a range of ESPs—including Gmail, Outlook, AOL, and iCloud.

Let’s go through its pros and cons: 

Pros:

• Offers comprehensive blacklist monitoring services.
• Helps you verify emails in bulk, so you never have to worry about bounce rates.
• Automatically removes emails with spammy content so your emails never land in spam.

Cons:

• No direct, straightforward email spam check functionality.

What do Users Have to Say?

7. Unspam Email

G2 Rating: 5/5⭐

Next on my list of the best free email spam checkers is Unspam.email. It gives you up to 10 free spam tests, 10 free email previews, and 3 inbox tests every month.

Personally, I had a great experience using Unspam. Checking my email for spam triggers was super easy. 

All I had to do was send an email to Unspam, and within 2 minutes, it gave me a comprehensive spam-check report based on my email’s content and authentication records.

What makes Unspam stand out from the other tools on this list is its email preview feature. It shows you exactly how your email will look across different devices—phones, tablets, and desktops—so you can optimize for every screen.

Let’s take a quick look at the pros and cons:

Pros:

• Provides you with a heatmap of the parts of your email that get the most attention.
• Shows you whether your test email contains an unsubscribe header or link.
• Unspam tests your email account’s authentication to ensure high email deliverability.

Cons:

• The monthly limit of 10 spam tests might be too restrictive if you need to check a lot of emails for spam triggers.

What do Users Have to Say?

8. Experte

G2 Rating: N/A

Experte is an easy-to-use, free email spam checker that uses SpamAssassin to test your emails for spam triggers. It also lets you know whether your email might be flagged by Gmail’s spam filter.

Experte offers a really simple spam-checking process—it’s just two steps:

• Send an email to a custom address provided for the spam check.
• Get a five-point report showing whether your email is likely to land in the inbox or the spam folder.

That’s it! Easy, right?

Now, let’s check out Experte’s pros and cons:

Pros

• Experte assesses your email account’s authentication records.
• The IsNotSpam feature lets you test newsletters and marketing emails for spam triggers.
• There’s no limit on how many emails you check for spam triggers.

Cons

• Does not offer too many insights on how you can reduce the spam score for your email content.

What do Users Have to Say?

Choose the Best Free Email Spam Checker!

With that list of free email spam checkers, today might just be the last day you ever worry about whether your emails will land in the inbox.

While each tool has its own strengths and limitations, picking the right one can still feel a bit tricky.

To make the right choice, start by listing the features you need—like API support, email authentication checks, or spam word detection.

Once you have that list, go with the free spam checker that checks all your boxes.

FAQs: Best Free Email Spam Checkers

1. What is the best email spam checker tool?

GlockApps is the best email spam checker tool because it offers highly accurate spam checks. It also provides detailed analysis of your email content, authentication records, and IP reputation to help you land in inboxes. 

2. Are there any email spam checkers that offer API support?

Yes! Mail-Tester and Postmark both offer simple and robust API support. Using this, you can directly integrate these free spam checker tools into your enterprise email infrastructure. 

3. How to avoid spam filters for bulk emails?

The best way to avoid spam filters for bulk emails is to set up & verify your email authentication records, clean your email lists, and remove any spammy words from your email content.