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How to Check Your IP Reputation (Tools & Step-by-Step)

By MailChannels | 4 minute read

If your emails are going missing, landing in spam, or bouncing back with cryptic SMTP errors, your IP reputation may be the culprit. Checking your IP reputation is one of the first steps to diagnosing email deliverability issues—and it’s easier than you think.

In this post, we’ll show you:

What IP reputation is and why it matters
The top tools to check your IP’s reputation
A step-by-step guide to running your own check
What to do if you find a problem

What Is IP Reputation?

IP reputation is the trust score assigned to the IP address you’re using to send email. Mailbox providers like Gmail, Outlook, and Yahoo use this score to decide whether to:

Deliver your email to the inbox
Redirect it to spam
Block it entirely

Your IP reputation is shaped by past sending behavior: spam complaints, bounce rates, spam traps, volume spikes, and more.

Poor IP reputation = blocked or filtered emails.
Good IP reputation = inbox placement and high deliverability

Tools to Check Your IP Reputation

Here are the best free and paid tools to evaluate your sending IP:

Free IP Reputation Checkers

Tool	What It Does
Talos Intelligence (Cisco)	Provides IP reputation rating (Good / Neutral / Poor) + blocklist status
MxToolbox Blacklist Check	Checks your IP against 80+ DNS-based blacklists (Spamhaus, SORBS, etc.)
Microsoft SNDS	Gives insights into how Microsoft views your IP (requires signup)
Google Postmaster Tools	If you’re sending to Gmail, get reputation scores and spam rate trends
Abusix Lookup	View if your IP is listed in real-time threat intelligence sources

How to Check Your IP Reputation (Step-by-Step)

Step 1: Find Your Sending IP Address

If you’re using a dedicated IP, ask your email admin or ESP for your sending IP.
If you’re using a shared hosting environment:

Send an email to your own Gmail or Outlook address
Open the email and view the full headers
Look for the “Received from” line to find the sending IP

Example:

vbnet

CopyEdit

Received: from mail.example.com (123.45.67.89)

Now you have your IP: 123.45.67.89

Step 2: Run Your IP Through Reputation Tools

Use the tools listed above to check:

Is your IP listed on any blocklists?
What is the reputation score (e.g., Good / Neutral / Poor)?
Is there any recent spam activity or suspicious volume?

Start with:

Talos Intelligence
MxToolbox
Google Postmaster Tools (if Gmail is impacted)

Step 3: Analyze the Results

If everything looks green—great. But if you see:

Listings on Spamhaus, SORBS, or Barracuda
A reputation of “Poor” or “Bad”
High spam complaint rates

—then you likely have a reputation problem affecting your delivery.

What to Do If You Have a Bad IP Reputation

If your IP is blacklisted or flagged:

Check your outbound email logs. Look for compromised accounts or spam-like traffic.
Stop sending from that IP temporarily. Prevent further damage.
Clean your email list. Remove bounces and unengaged recipients.
Submit delisting requests to blocklist operators like Spamhaus.
Use a smart SMTP relay service like MailChannels to isolate bad traffic and protect your IPs.

Pro Tip: IP Isn’t the Whole Story

While IP reputation matters, mailbox providers now heavily weigh domain reputation too.

Read: IP Reputation vs. Domain Reputation: What’s the Difference?

Want to Skip the Headaches?

MailChannels Smart Host automatically protects your IP reputation by:

Routing email through clean, trusted IP pools
Blocking spam before it ever reaches the internet
Providing actionable SMTP diagnostics via ResponseAnalytics

Try MailChannels for Free →

Summary: IP Reputation Check Checklist

Find your sending IP from headers or email admin
Run it through Talos, MxToolbox, and Gmail Postmaster
Note any blocklist appearances or “Poor” scores
Investigate spam or compromised accounts if flagged
Clean your list and use a smart relay for protection