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What is IP reputation and are there ways to improve it?

Your IP reputation will determine whether your emails get to the top of the inbox, or go straight to the spam folder. We’ll show how your IP reputation is calculated and the steps you can take to improve it. The result will be higher engagement for the email marketing campaigns you worked so hard on.

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You know the old expression, “you’re only as good as your word”? In today’s complex marketing climate, Internet Service Providers (ISPs) judge your trustworthiness as harshly as people offline. That’s right – ISPs are constantly on patrol for fraudsters and phishing enthusiasts trying to prey on innocent inboxes. And your Internet Protocol (IP) reputation determines whether or not your emails are blocked or sent to the spam folder.

Let’s say you’re a digital email marketer who puts hours of effort into crafting the perfect newsletter content. It could be devastating to find out that your online activity has raised red flags preventing your audience from receiving your content. Your IP reputation could be at stake, so let’s look at ways to improve it to ensure the success of your email marketing campaigns.

What is IP reputation?

All internet activity is linked to an IP address or a set of IP addresses that work as a network. If a given network or IP address exhibits suspicious behavior, ISPs could label the entire network’s IP reputation as poor. Each IP address will have a reputation score between zero and 100. This is different from a domain reputation, which considers the activity of your branded domain, not just the dedicated IP address you are sending your emails from.

Why is IP reputation crucial?

When ISPs scan the internet to see a given IP address's risk score, they'll make a quick judgment call on whether the users from that address behave in the name of good or evil.

Having a solid IP reputation means your ISP recognizes that your IP address has good intentions, unlike those of bots, fraudsters, or cybercriminals. If your activity shows illegitimate browsing behavior, your IP address could be flagged.

Basically, if you’re an email marketer, you should do everything to make your IP reputation as sterling as possible (and obviously don’t engage in suspicious activity that could be flagged). You want to ensure your audience receives your marketing emails and that your online behavior doesn’t land you on the blocklist.

How to improve your IP score

If you perform an IP reputation check and find that your score isn’t favorable, you can implement the following practices to improve your IP reputation.

1. Identify which blocklists you’re on

If you’re wondering, “How can I check my IP score and improve it?” The first step is to find out which blocklists have identified your IP address as fraudulent.

2. Delist your IP address

Once you know which blocklists have your IP address, navigate to those sites, and they should have the steps you need to follow to delist yourself. Remember that successfully appealing to delist yourself usually takes about 24 hours.

Unfortunately, you’re not out of the woods once you’re off those lists. You need to be extra vigilant to keep yourself and your IP address from returning to those blocklists. It gets harder to delist yourself each time your IP score is negatively impacted.

3. Keep your bounce rate low

If you’re an email marketer, giving your email list some TLC will help ensure you’re not mass sending your marketing messaging to email inboxes that won’t receive them. You can do this manually or with an email address validation service. Plus, keeping an eye on your email list might help you catch potential spam traps or email addresses that can trigger negative reviews or spam replies to your content.

4. Implement an IP warm-up period

This is when you slowly increase the volume of emails you’re sending to show anti-spam monitors your cadence and establish your reputation. The recommended strategy is to send 300 emails on day one, adding 20% every day until you reach 100% of your contacts. Doing this will maximize your potential to have a positive IP reputation. Using a warm-up strategy will also influence your sender score and email reputation. Win-win!

The recommended strategy for warming up your IP.

5. Other tools to keep on your radar

Maintaining a solid IP reputation isn’t a one-and-done affair. You’ll have to periodically ensure that your reputation isn’t hindering your email marketing efforts. Some other tools include:

How is your IP reputation score calculated?

Six major factors can lower your IP reputation score, and it’s important to be familiar with them:

1. Complaints

Flagging an email as spam is a direct complaint by the recipient. The recipient can flag any email with a simple click thanks to the “mark as spam“ button present in most electronic messaging interfaces.

The number of spam complaints has a high impact on IP reputation score. To avoid any negative impact on your deliverability, incorporate practices to keep your emails out of the spam folder.

If you’re a Mailjet client and want more details about managing spam complaints, you can refer to our documentation page about various email status.

2. Errors/incorrect addresses (soft and hard bounces)

An inbox that is full or temporarily unavailable leads to soft bounce. On the other hand, if the email address is misspelled or does not exist, this is considered a hard bounce. It may indicate that the sender is not keeping their contact lists cleaned and up-to-date.

3. Spam traps

Spam traps, also called honeypots, are email addresses made to trap spammers. They can be created purposely, but old email addresses can also turn into spam traps.

The administrators of these traps look for situations where no opt-in has ever been confirmed. So they know that every email received has not respected best emailing practices (nor most laws). Purchased or rented lists systematically contain a significant number of these spam trap email addresses, which is why Mailjet prohibits you from using third-party lists.

4. IP network

IP addresses can be grouped into IP networks and the reputation of the whole network can directly impact your individual IP’s reputation.

Think about it this way: If your IP address is like your home address, then your IP network is your neighborhood. And unfortunately, it’s possible to live in a “bad neighborhood.”

Your IP network can hurt your IP reputation sender score when enough bad actors are sending spam, fraud, or committing cybercrime using IPs that are part of your network. Your IP address reputation might get even more damaged if it’s part of a botnet or network of computers infected with harmful malware.

5. History of the IP

It’s important to keep in mind that this score isn’t only based on one or two incidents. In fact, your entire IP reputation history is taken into consideration when ISPs calculate your IP risk score. And if we’ve got you questioning every internet search you’ve ever made, we apologize.

6. Age of the domain

The age of the IP is also closely linked to its history. Older websites’ domain names and IP addresses are considered more stable than newer ones. So using or acquiring an older domain name will give your IP a better reputation across the internet.

Wrapping up

As you can see, there’s a broad scope of things to consider when calculating your IP reputation. One of the most efficient and effective ways to stay on top of your IP reputation is to manage your email delivery rate. And luckily for you, we’ve got the tools to help you optimize your email reputation.

Mailjet will arm you with the ability to accurately monitor the metrics that tell the story of how your audience engages with your material. As an email service provider, we can help you track your:

  • Open rate

  • Click rate 

  • Unsubscribe rate

  • Spam complaints

Once you’ve released some email marketing content into the world, Mailjet’s platform can help you analyze this data to measure its performance. Then you can make an educated decision on what elements to change to improve your content’s effectiveness.

Improving your email marketing content is a marathon, not a sprint. We recommend getting into the mindset that you should constantly be adjusting. When you think you’ve nailed the perfect combination of excellent copy, branded images, and powerful templates, use A/B testing to keep tweaking and improving.

Want to learn more about email deliverability? Download our ebook, “Landing in the inbox: Email marketing deliverability basics”.


Landing in the inbox: Email marketing deliverability basics

Don’t let great emails go to waste. Discover everything you need to know to land in the inbox.

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