Blog Manager

Universal Article/Blog/News module

Email Reputation Clusters and Fingerprinting

Like Up:
Like Down:
06 Jan 2021

Using emails is an effective strategy for marketing and connecting with your customers while also promoting your business. There are some factors to be kept in mind while sending out emails in order to make sure they don’t end up in the spam folder.

Email sender reputation is one such important factor. Let’s dig out more about it.

What is Email Reputation?

Email sender reputation is like a score that is assigned by the Internet Service Provider for an organization that sends emails. Maintaining a high score is important because the higher the score will be, the more are the chances that the ISP will deliver the email to the recipient’s inbox. If the score is low, there’s a chance that the email will end up in the spam folder or it might not get delivered at all.

Each ISP can have different criteria for assigning a reputation score based on different factors thus a sender can have different reputation scores for different ISPs.

How Clustering And Fingerprinting Affects Deliverability

Email providers are equipped with smart machine learning algorithms that can filter out spam emails so that only the important one reaches the recipient. These algorithms judge data like spam reports, the number of times email was opened, engagement reports, etc., and apply them to a cluster of data. This helps in coming up with a fingerprint of important and spam emails.

The ISP then checks if a cluster of elements signals unwanted email, it will then assign a negative reputation score and vice versa.

Now if a number of spam complaints are registered against an email, the service provider will look at the email and identify the factors (one or more) that are common in spam emails. The more elements that appear in spam together, the more the reputation of that cluster will build. When the inbox provider identifies a significant amount of spam emails and identifies the common factors among them, the cluster of factors will form a reputation fingerprint which will help the provider in identifying future spam emails.

How Can A Cluster Gain A Negative Reputation?

A cluster can start developing a negative reputation if it frequently appears in spam emails. Actions of other senders in the world can also result in certain types of content getting a negative reputation. Sometimes spammers or scammers use certain topics or content that, while important for your industry, might be used to spam others. This results in building a low reputation for such topics.

Optimizing Email Infrastructure

If you understand how emails are clustered to create fingerprints for detecting spam and other types of emails, it can help you in crafting more efficient emails to avoid ending up in spam.

In case you are sending two types of emails, marketing, and transactional emails. It is recommended that you use a different infrastructure for both types of emails. The reason for this is that marketing emails might get reported for spam and the ISP might recognize it as spam. If you use the same structure for the transactional emails as well, these important emails might end up in the spam folder, which is undesirable.

Understanding clustering can also help the sender in making suitable changes to the email in case any delivery problem arises. For example, if your IP is added to the deny list most of your outgoing emails will not be delivered. In order to solve this issue, one might think of changing the IP. But a better approach would be to go through your previous emails and look for the pattern that might seem like spam.

You can try to locate the problem due to which the recipients might feel that they're being spammed with irrelevant content. Once the problem is identified you can try changing the structure and content of the email accordingly to restore your reputation score.

If the recipients are not opening up your emails and engagement is low then you should consider working on creating more engaging content or you can limit your emails to people who engage.

If your emails are getting more spam reports then a good tactic would be changing the email structure.

If the content is good but the emails are still ending up in spam folders then you can try investigating why this is happening. One of the reasons might be that spammers are using the same topic or structure.


If you send out emails frequently, you might at some point encounter delivery issues. These delivery issues are not always because of a bad IP. Senders face delivery issues because their emails generate a signal that might match that of unwanted emails in the eye of the ISP.

There are several ways to increase your email deliverability. The best one is to keep creating engaging emails that will compel the recipient to open them. All this can be done effectively if the sender is well aware of email reputation building techniques and how the fingerprint testing works to filter out spam.

No comments yet...
Leave your comment

Character Limit 400