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You are doing your best to follow all the rules and send emails to your clients, making both customers and mailbox providers happy but are not getting the desired results.

If you want to monitor your email deliverability and improve the process, IP reputation is the first thing you need to check. It is the only way to check how mailbox providers think of your email campaigns and whether they end up in your subscribers’ inbox or spam folders.

In this blog, we’ll explain everything about IP trustworthiness and reputation and why it matters for all businesses.

What is IP Reputation?

IP reputation is the behavior quality of an IP address. IPs used by bots and cybercriminals will have a lower reputation and high-risk scores as compared to IPs used for legitimate online browsing.

IP addresses with a string reputation mean that they have never been associated with any malicious activity or have been the target of malware, hackers, and other malicious actors. If an IP has a history of small domains, locations, and such, it will have a good reputation.

However, if an IP is currently benign, but has a bad history of hosting malware in the past, phishing sites, or other malicious activity, then the IP still poses a threat to users. The higher the risk, the worse is the reputation of the IP.

Why Does IP Reputation Matter?

A strong IP address with a good reputation reflects that the device with the address is trustworthy for information and communication. So why is IP reputation important?

If you own a business and want to reach out to your customers and clients via email, your IP reputation and trustworthiness will affect your email campaign. 

If you have a bad reputation, your email will be flagged as spam. If your website gets compromised or the server you use is used for fraudulent activity, inbox providers like Gmail, Yahoo, etc., will flag your emails.

Moreover, your reputation will go down, so any email sent by you will not be considered trustworthy and you will suffer from spam traps. Even if you are trying to run a great email campaign, it will get you nowhere if your reputation is bad.

How Do I Find my IP Reputation?

There are various tools available online to check the reputation of your IP address. These tools measure the score using multiple parameters to gauge the reputation.

Here are some factors that are used for checking the reputation of your IP address:

  • Age of the IP addresses
  • Domain reputation
  • IP address category
  • Popularity
  • History of the IP address
  • The reputation of the associated URL
  • Any previous malicious internet objects
  • Spam rates
  • Real-time performance
  • Hosting provider
  • Presence of the IP on any blocked lists online
  • Hosting location
  • Presence of code or downloadable files

What is an IP Reputation Attack?

IP reputation attack is an attack that uses IPs with a bad reputation to blacklist IPs that are good. In this attack, the attackers are usually unaware of the reputation of their own particular IP address.

An IP reputation attack can occur when a user sends small packets of data multiple times that is more than your bandwidth. It gradually transforms into a DDoS attack on your IP address, thus blacklisting your IP, which affects your reputation.

IP trustworthiness and IP reputation issues are problematic for most internet users, especially small business owners who use their personal devices for work.

What IP Reputation Tools are Available?

There are plenty of checker tools that are available online to check the IP reputation score of IP addresses. These tools have IP addresses ranked according to their reputation.

1. Google Postmaster Tools


Google Postmaster Tools (GPT) is used to help monitor email and IP performance and potential issues with deliverability. This is one of the few free IP reputation services that offers marketers access to important data like reputation, performance stats, security, and more about IPs and emails.

The tool also shows you data about spam, encryption success rate, SPF/DKIM/DMARC failures, and more. However, it is only available for GSuit and not other mail providers like Microsoft, Yahoo, etc.

Here are some metrics used by GPT to calculate your reputation include:

  • Sending volume
  • Spam complaints rate
  • Reject rate from senders
  • General infrastructure
  • Unknown users
  • Encryption

2. Sender Score by Validity


Sender Score is another IP reputation service used to calculate the health of your email program and the reputation of your IP address. It calculates the reputation of the sender using important metrics that are important for mailbox providers like Gmail, etc., and email subscribers as well.

Sender Score is based on a scale of 0-100:

  • A score of 0-70 means you need to repair your reputation as it exhibits malicious behavior.
  • A score of 70-80 means that you have a good reputation with low threat status, but there is room for improvement to optimize your email program.
  • A score of 80+ means you have a great sender reputation, and your email campaign qualifies for preferential treatment from your mailbox provider.

3. Talos Intelligence by Cisco


Another public tool to check reputation and trustworthiness is Talos Intelligence by CISCO. For checking the reputation, it has a Web Reputation grade that assigns grades to each IP based on various measures. These grades include unknown, poor, neutral, and good.

Some stats that it shows include:

  • Email reputation
  • Web reputation
  • Email volume
  • Spam level
  • Added to block list (spam, abuse, etc.)
  • Network owner

Here are details of Talos web reputation threat levels and what each grade means:

GoodTrusted reputation that indicates exceptional safety and security
NeutralFavorable safety but it has been evaluated before and poses a risk
PoorUntrusted with exceptionally undesirable behavior with malicious past
UnknownNot evaluated before due to lacking features to create a threat level verdict

4. BrightCloud’s IP List


BrightCloud’s threat intelligence also offers an IP list to check IP address reputation. However, unlike other tools, this one does not provide data in detail with each metric defined separately.

BrightCloud’s IP address reputation index includes scores ranging from 1-100.

01-20High RiskHigh-risk IPs – will deliver DDoS attacks, & other malicious activities
21-40SuspiciousSuspicious IPs – will deliver attacks on your infrastructure
41-60Moderate RiskBenign IPs – potential risk of attacks on endpoints
61-80Low RiskBenign IPs – low-security risks and risk of attacks
81-100TrustworthyClean IPs – have not been tied to suspicious activity

5. MultiRBL


MultiRBL IP reputation tool provides detailed information about various metrics that affect the reputation and trustworthiness of your IP or domain. The tool uses various tags for each test like Not listed, Blacklisted, Brownlisted, Yellowlisted, Whitelisted, Neutrallisted, and Failed. 

When you search your IP on the platform, it checks various parameters as follows:

  • DNSBL Blacklist Test (spam listing)
  • DNSBL Informationallist Test
  • Abusix Mail Intelligence Test
  • barracuda Reputation Block List
  • BlockedServers NetScan RBL
  • IBM DNS Blacklist

How Can I Improve IP Reputation?

If you are a small business owner and are using an IP with a negative reputation, you must take measures to improve your trustworthiness. Why? Because reputation can impact your productivity, especially of your email marketing campaigns. Chances are that due to a bad reputation, your emails are ending up in the spam folder.

Here are a few simple ways to improve your IP reputation and increase your chances of reaching out to your clients and customers via email:

Keep your business and personal email servers separate:

One way to improve your reputation is to keep your business and personal email servers separate. It will reduce the number of emails sent from one server, boosting your trustworthiness and help you prevent spam.

IP warming:

If you have decided to go with separate servers, you need to do some IP warming. To do that, make sure to remove email addresses that mark your mail as spam, clean up your database and remove inactive recipients.

Check for malware:

Check your servers to ensure it is not being used as zombie machines to spread malware.

Set up a WAF:

Make sure to set up a web application firewall to filter out malicious traffic. Some filters you should use in WAF include geographical location, anonymous proxies, and risky/blacklisted IP addresses.

Review all subdomains:

Apart from the top-level domain, make sure to check your subdomains. Each subdomain has its own reputation, which makes it easier to detect issues.

Set up SSL/TLS:

Make sure to set up SSL and TSL for encryption to protect your data. It not only improves your security but also verifies your IP address.

IP Reputation Email – What is it and Why Does it Matter?

IP address reputation is a score that gauges the worthiness of your email, which affects the health of your email program. It is important for businesses because mailbox providers like Gmail and more use these metrics to determine your reputation as the sender, including spam, blacklists, and more.

So, if you don’t want your email to end up in a customer’s spam folder, you need a good IP address reputation. You can check the score using any of the tools mentioned above to make sure your emails get delivered to recipients and do not end up in the spam folder.

What is a Bad IP Reputation?

IP addresses are assigned a bad reputation when they are associated with malicious activity like high levels of spam, malware, viruses, or more. These IP addresses are checked to make sure they don’t belong to machines and bots. IPs with bad reputations may include:

  • Compromised devices (zombie machines) are used to send out spam.
  • Open proxies through which untrusted emails pass easily.
  • Systems that are used to spread spam on the internet.

Open proxies are computers that allow emails to be sent from machines. These can be compromised servers or personal computers.

A zombie computer is a device attached to the internet that has been compromised via virus or malware. Such machines can be used and controlled from a central location without the knowledge or consent of the owner of the computer. These are common delivery methods for spam worldwide.

Make sure to use security tools like firewalls, VPNs, and anti-malware software.


IP reputation list identifies IP addresses that are used to send unwanted requests. With the IP reputation list, you can block requests that are coming from IP addresses with a bad reputation. This way, you can optimize Web Application Firewall performance as it filers requests that you don’t want to process.

You can fix poor email reputation by identifying, targeting, and removing inactive recipients, which will help you get a more engaged list. By sending emails to a list of subscribers who want to receive your content, you can boose engagement which will help repair your email reputation.

A website or IP may be blacklisted if its content is not deemed appropriate. This could be due to black market trade, pornographic material, or sensitive subjects such as arms and weapons dealing. ISPs and government agencies could block such websites and IPs, which will prevent users from accessing them.


IP reputation is very important for businesses as it could either make or break your marketing campaign. With a great reputation, your subscribers will be able to enjoy your newsletters and content without ending up in spam. There are plenty of tools available online to check the reputation and trustworthiness of your IP address and ways to improve the score for building trust.