What is Email Reputation Check and How to Do It? (2025)

Your email reputation (sender reputation) plays a huge role in where your emails land – the inbox, promotions tab, or spam folder.

If your emails are ending up in spam (or if you want to make sure they never do), then this blog is exactly what you need.

In this blog, I’ll walk you through:

• What is an email reputation check?
• Why can you check your email sender reputation?
• How can you perform an email reputation check for free?

So keep reading to stay out of spam folders for good.

What Is an Email Reputation Check?

An email reputation check gives you insight into how well Email Service Providers (ESPs) trust your email accounts and domains.

By doing an email reputation check, you can find out where your emails are likely to land —

• In the inbox (where they should be)
• In the promotions or updates tab (where they might get ignored)
• Or worse, straight into the spam folder (where they’ll probably never be seen).

So, what do ESPs use to decide whether your emails deserve the inbox or the spam folder – email sender reputation.

What Is Email Sender Reputation?

Email reputation is a score or rating that ESPs use to decide whether they can trust emails sent from your domain or email accounts.

• A good reputation means your emails are more likely to land in the inbox.
• A poor reputation means your emails go straight into the spam folder.

Your sender reputation is built over time based on how people interact with your emails, and other factors that I have covered in the next section.

What Affects Email Sender Reputation?

Now that you know what sender reputation is, let’s break down the key factors that actually shape it:

• Spam Complaint Rate: If too many users think you’re sending them irrelevant emails and they mark your emails spam, your email reputation will take a massive hit!
• Bounce Rate: Your emails bounce if they are sent to invalid, non-existent, or inactive email addresses. So, a high bounce rate signals to ESPs that you are mass-sending emails, which is usually done by spammers.
• Sending Volume: One of the things that ESPs hate the most is irregular or inconsistent sending patterns. So, if you send too many emails in too short a time, the ESP will lower your email reputation.
• Engagement: The more recipients engage with your emails by opening, clicking through, and replying to them, the higher your sender reputation will be!
• ESP Blocklists: If your domain or IP ends up on an ESP’s blocklist or a public blacklist, your deliverability takes a huge hit. It’s important to monitor and stay off blocklists if you want to keep a healthy sender reputation.

In short, there are five very important and predictable factors that heavily influence your email sender reputation!

Why Is It Important to Check Your Email Sender Reputation?

Okay, so we’ve seen that email sender reputation is how an ESP determines whether you’re a trusted source of email communication. 

But is it really that important? Can a low sender reputation really make that much of a difference?

Absolutely! Your email sender reputation is one of the most important aspects that affect your email deliverability.

In fact, you can safely assume that sender reputation is the golden metric that ESPs use to decide where to send your email: the inbox or the spam box.

So, it’s highly recommended that you check your email reputation from time to time when doing outreach.

How to Do an Email Reputation Check Using Dedicated Tools?

Now that we’ve explored what email reputation is and why it’s critically important, let’s find out how to check email reputation.

And if you’re worried that this might be a challenging, even difficult process, don’t be! I’ve curated a list of 5 very simple tools you can use to check your email sender reputation.

Let’s check them out one by one:

1. Google’s Postmaster Tools
2. Sender Score
3. MxToolbox
4. Talos Intelligence
5. Microsoft SNDS

1. Google’s Postmaster Tools

Google’s native Postmaster Tools is a free-to-use platform that helps you visualize and analyze your email deliverability.

It’s a very simple tool that offers a wealth of data on your email account’s deliverability metrics. Using Postmaster Tools, you can examine your:

• Email Sender Reputation
• Spam and Spam Complaint Rate
• Authentication Records Status
• Delivery Errors or Bounce Rates

2. Sender Score

Sender Score is another great tool that helps you understand your email sender reputation and get information on your domain health.

It assigns you a score between 0 and 100 based on your email infrastructure, sending patterns, and IP reputation. 

Here’s what makes Sender Score different from a basic platform like Google’s Postmaster Tools:

• It allows you to understand why your emails are bouncing
• It helps you verify your email lists
• It enables you to monitor ESP blocklists 
• It lets you compare your deliverability benchmarks against global standards

3. MxToolbox

MxToolbox is one of my favorite email reputation checker tools because it gives you a detailed report on five different aspects of your email reputation.

These include:

• Basic problems with your email authentication
• A DNS check that ensures that your email is configured properly
• Blacklist report to ensure you’re not blocked from sending emails
• A server test to help you understand whether specific ESPs are blocking your emails
• A web server check that enables you to check if a web server is flagging your emails

Moreover, MxToolbox also has a paid service where you get solutions to fix any issues hampering your sender reputation.

4. Talos Intelligence

Talos Intelligence is a free-to-use, Cisco-powered email reputation checker. 

It helps you understand two major things: 

• Whether your email has been blacklisted
• The reputation of your domain

One thing I like about Talos Intelligence is that it helps you submit a ticket if you think that your domain has been unfairly blacklisted!

Plus, you can also use Talos to understand global spam email sender and spam data, filtered by region and hosting services provider!

5. Microsoft SNDS

Just like Google, Microsoft also has its own native email reputation checker service, called the Smart Network Data Service, or SNDS.

SNDS is a dedicated email reputation checker that primarily works with Outlook. Its main goal is to help you understand and manage your email reputation. 

It does so by providing you with detailed reports on spam complaints and helping you resolve deliverability issues.

What Are the Best Practices to Follow to Have a High Email Reputation?

I’ll share a few best practices that you can follow to make sure your email sender reputation stays strong and your emails consistently land in the inbox.

1. Authenticate Your Email Account
2. Get Email Lists from Trusted B2B Data Vendors
3. Use Double-Opt-In for Marketing Emails
4. Use an Automated Email Warm-Up Tool

1. Authenticate Your Email Account

Email authentication is one of the most critical aspects of your email infrastructure – It helps you avoid phishing and spoofing attacks.

According to ESP guidelines, there are three authentication records you must set up:

• SPF: Sender Policy Framework
• DKIM: Domain-Keys Identified Mail
• DMARC: Domain-based Message Authentication, Reporting, and Conformance

2. Get Email Lists from Trusted B2B Data Vendors

As we’ve seen, high bounce rates can severely reduce your email sender reputation.

This is usually due to two reasons:

First, you’ve either made a small error in typing an email address. This is an easily fixable error, especially if you use an email verification platform before sending emails. 

Second, you’ve bought an email list from an unverified vendor. Again, I recommend eliminating this problem by only getting email lists from trusted B2B data providers!

3. Use Double-Opt-In for Marketing Emails

In recent years, privacy has come to play a huge role in determining sender reputation. This is largely due to legal requirements that stress compliance with privacy laws of different countries and regions.

To avoid a drop in your sender reputation because of this, I suggest using a double opt-in mechanism for marketing purposes.

It’s a simple way of obtaining the consent of your recipients when they sign up for your email list!

4. Use an Automated Email Warm-Up Tool

I’ve often noticed that people struggle to increase the sender reputation of their new or dormant email accounts.

And this happens even though they’ve followed all the best practices I’ve mentioned above.

So, what’s the solution in such cases? 

Simple: establishing a pattern of sending emails to and receiving replies from highly reputable email accounts. 

And that’s where an automated email warm-up tool comes in! It will: 

• Send a set number of emails to highly reputable email accounts 
• Open the emails, take them out of the spam folder, and mark them important
• Reply to a percentage of the emails sent through your email account
• Gradually increase the number of emails sent and replies received

In short, an automated email warm-up tool will help you win the trust of your ESP by creating human-like conversational threads through your email account!

Don’t Leave Your Deliverability to Chance!

A high email reputation is a prerequisite for successful cold emailing and lead generation.

Simply put, it’s too important to leave to chance or half-measures…

What you need is a surefire way that guarantees a high email sender reputation – and that’s exactly what TrulyInbox offers!

Sign up for the forever-free plan and experience how successful email warm-up can supercharge your email deliverability…

What is Email Reputation Check: FAQs

1. How often should you check your email reputation?

In my opinion, you should check your email reputation at least once a week if you want to ensure that your emails are landing in your recipients’ inboxes. However, if you rely on email marketing to generate leads, I recommend checking it every day that you’re running an outreach campaign. 

2. What is the best way to check email reputation?

From what I’ve seen, the best way to check your email reputation is to use a free tool like Google’s Postmaster Tools or Sender Score. Such tools will help you track key deliverability metrics and provide a visual understanding of your email sender reputation.

3. How to improve email reputation?

The best way to improve your sender reputation is to use an automated email warm-up tool. It’ll help you establish a pattern of email conversations with highly reputable email accounts and win the trust of your ESPs.