What is IP reputation?

An organization’s IP reputation depicts the quality of its email sending environment. Like any good reputation, a positive IP reputation is a valuable asset and must be protected. This means monitoring the reputation of your systems, public IPs and domains as well as the IP and domain reputation of those that interact with your network.

Compromised networks are often used for malicious purposes. If compromised, your system could become a spamming platform or part of a botnet, used for a distributed denial of service attack, or for corporate espionage.

IP addresses that are open proxies, or that send high volumes of spam or viruses to users or spam traps, are assigned a negative reputation. Anti-spam organizations analyze these IP addresses to see if they belong to machines that should not be sending mail.

Every email can be traced back to an IP address, and IP addresses gain an IP reputation based on past incidents. IP addresses are also part of a larger sending environment, typically owned by your email service provider (ESP). If an ESP has allowed IP addresses in its environment to send spam or unwanted bulk email in the past, the IP reputation for that ESP is affected. Poor IP reputations can lead to more bounces and slower delivery, for all customers in that ESP environment.

It is important to choose an established ESP with a good reputation. An ESP with many high-quality customers has faster email delivery, and is given more forgiveness when inevitable sending mistakes happen. On the other hand, ESPs with a poor IP reputation will have more email delivery performance issues.

How can you tell if your ESP has a good IP reputation? ESPs with high customer standards typically have better IP reputations, so when creating your account, it’s a good sign if your ESP is responsive to your requests and asks you to fill out detailed questionnaires.

How to monitor your IP reputation

It is also important to monitor your IP reputation for any changes. When you track your IP reputation, it enables you to act quickly to secure your system when necessary. You must conduct an IP reputation lookup to monitor the status:

  1. Open your message headers to see the actual IP address being used to send over your message.
  2. Use public IP check tools to see the reputation of your IP address. (ReturnPath Sender Score service and Cisco’s Talos Intelligence “Email Reputation” are two services.)
  3. Be sure to do an IP reputation lookup regularly, to monitor for any changes.

If you find your IP has a negative reputation, reach out to your ESP to see how it can be corrected.

 

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