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
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
