deliverability letter

Sending Reputation and Sender Score: What Are They and Why Are They Important?

Thoughts by Gracija Atanasovska • Content Team Bento

Who doesn’t like a good score? No matter what line of work you’re in - academia, tech, sports… Everybody likes to see a good score!

Well, the same goes for email campaigns. Sender score and sender reputation are important metrics in email marketing campaigns, and that’s exactly what I want to talk about in today’s article.

For those of you who are still new to the email marketing world, it’s understandable that you get lost in all the metrics and industry terms. But no worries, I’m here to guide you.

I’ll explain what sender reputation and sender score mean, in easy-to-understand terms, and show you why they’re important in email marketing campaigns.

So let’s get started, shall we?

What Is Sender Reputation?

Email sending reputation, or email sender reputation, is a metric that involves several different types of reputation which together serve to determine whether you’re a spammer or not. Essentially, it’s based on past email delivery practices.

The most important types of reputation that dictate sender reputation are:

  • IP reputation
  • Content reputation
  • Domain reputation

Sender reputation describes the reputation of the IP address from which you send your emails. It’s designed to give email providers information that can help them decide whether you are a potential spammer. Some of the important factors it is based on are content quality and contact quality, as well as the levels of engagement of emails sent previously from that same IP address.

Next, I want to give you a brief overview of the three subtypes of reputation which dictate sender reputation.

IP Reputation

As sending emails became more widespread in the middle of the 1990s, spam also began to take a bigger hold and soon after grew into a pretty serious problem.

So, as a way to fight and prevent the onset of spam messages, the large ISPs (internet service providers) came up with IP reputation and began using it as a metric with which they measure and analyze the quality of sent emails.

IP reputation measures how much the emails you sent from your IP address are actually wanted by the recipients. They do this by measuring bounced emails, bulk email, and spam complaints.

As time went by, IP reputation lost its effectiveness as a sole metric of sender reputation, mostly because it didn’t have the option to look at how different IP addresses could actually send identical (junk) emails to users.

Content Reputation

As technology advanced throughout the years, in the 2000s, ISPs started to develop new methods with which they could measure a sender’s email quality. They managed to do this through the content reputation metric.

Content reputation is based on certain criteria which serve to determine the quality of the sender’s email campaign content.

Some types of problematic or downright dangerous content are more obvious than others. For instance, a virus or malware attached to an email and sentences which ask for bank details or other personal info are some examples that are easier to detect.

However, the content reputation of a sender can also go down because of emails getting low open rates, emails getting blocked or flagged, as well emails leading people to unsubscribe.

Together, IP reputation and content reputation offer a better set of criteria and measurements to create a clearer, more complete picture of sender reputation.

Domain Reputation

Domain reputation is another development in the fight against spam emails. As the authentication systems developed more and more, the ISPs also came up with a metric that determines the quality of the domain’s authenticated emails. That’s because IPs and domains can differ from one another. Some people can share IPs and yet send emails through their own domains. Thus, the domain reputation became a factor in determining the sender's overall reputation.


As a wrap-up of this section, we can say that an IP reputation’s job is to determine the quality of the sender’s emails based on their emailing history, aka based on the history of the actual address from where the emails are sent.

Content reputation, on the other hand, looks at the type of content that comes from that sender’s address and based on its own criteria, determines whether the providers can trust the sender or not.

And lastly, domain reputation is a metric that determines the credibility of the authenticated emails passing through a certain domain.

Hopefully, having made that clearer, I now want to turn to the sender score and give you a definition of what this is.

What Is a Sender Score?

Sender score is an algorithm that rates the sender reputation on a scale from 0 to 100. It rates the IP address of every outgoing email server with this scale. The score is based on the quality of the email campaigns, their size and frequency, and also the user’s interaction with them.

The sender score is not a fixed metric - it will keep on changing as your email sending habits and the reply and engagement habits of your recipients change.

This score is the one that determines whether the email providers will deliver the emails to the designated users’ inboxes.

The thing about sender score is that there isn’t one single metric that can measure it. Instead, you have to choose a reliable, good quality email marketing service that will provide you with the scale and specific criteria which you have to maintain in order to keep a good sender score and sender reputation.

When the sender score is being calculated, usually millions of inboxes are being analyzed (by using non-personal data) from various ISPs, security companies, and spam filters, all with the intention of coming up with a clear picture of the sender’s email campaign sending habits. They are usually calculated every 30 days or so.

Are Sender Score and Sender Reputation the Same Thing?

I know you’ll be tempted to think this, but the answer is no, they aren’t.

Sure, the sender score can indicate the overall email reputation of the sender, but by no means are they the same. You can look at the sender score as a metric, a number that makes the sender reputation seem more tangible and more clear.

How Can You Measure Your Sender Score?

You can measure your sender score through your own email marketing software or platform.

There’s also a way to do it outside a platform by going to, filling in the required details, and receiving the metrics you need.

How Can You Improve Your Sender Reputation and Sender Score?

I mentioned earlier that sender reputation consists of other reputations that determine your deliverability quality and your content quality, among others.

The IP reputation refers to a metric that shows how many recipients actually want to see emails coming from that particular IP address.

The content reputation measures the consistent quality of your email content - how much of it is spam and how much of it is actually relevant for the recipient.

Lastly, the domain reputation is responsible for checking the email sending practices from your domain, which gets validated through email authentication procedures.

If you want a good overall sending reputation and a high sending score, you have to make sure that all of these other reputations are taken care of first.

That’s why the next thing I want to talk about are some methods that will help you maintain these metrics and improve your sender reputation and sender score, or at the very least, help you ensure they’re kept in check!

Authenticate Your DKIM and Your SPF

Authenticating your email account is very important because it’ll help you fight spam. When you do this, make sure that only a particular list of IP addresses can send emails from your domain. This helps to keep spammers at bay and away (rhyme not intended!) from your email domain.

And that is also why you have to authenticate your DKIM (aka your DomainKeys Identified Mail) and your SPF (aka your Sender Policy Framework).

You can look at DKIM as a specific signature that you put in your email campaigns. It serves as powerful proof for the recipient’s ISP that your emails are indeed valid and have authenticated domains. DKIM uses public-key cryptography as a way of verifying that the email message was really sent from an authorized email server. If the DKIM signature matches, then the email lands in your recipient’s inbox. If, however, it doesn’t match, then it’ll land in the spam folder or it will simply bounce.

And what about the SPF? Well, the SPF is another form of email authentication protocol that contains a list of authenticated IP addresses from a particular domain. They allow the owner of the domain to choose precisely which servers то send their emails from.

Both DKIM and SPF operate together so you can be safe from spoofing attacks (when a sender basically uses your domain to send spam).

Create Different Sub-Accounts According to Your Email Campaign Needs

Different email needs call for different sub-accounts. By separating your transactional emails from your marketing emails, for instance, you’ll be much more organized and marketers will have a much easier time keeping track of different email metrics.

This will give you a clearer view of your marketing emails’ scheduled sending, the types of marketing emails you’re sending, the frequency with which you send triggered transactional emails, and the different types of transactional emails that get triggered, among else.

When you separate marketing emails from transaction emails, you can also locate deliverability issues more easily, and not make a mistake where you actually pass them on to the other category when there’s no need.

For example, imagine if your transactional emails went straight to the spam folder because the filtering system of an ISP identified the sender as a spammer based on the marketing emails they were sending. I mean, why should you get into this kind of trouble when you can easily avoid it?

Take Charge of Your Engagement Data

Email engagement data keeps the information about how much your users are actually engaged with your email campaigns. This kind of data includes details such as:

  • Email open rates - this is one of the most common metrics in email marketing and it basically keeps track of how many of your users open your email campaigns, i.e. the percentage of users who open your emails.
  • Email click rates - this is another common metric in digital marketing which focuses on the percentage of users who actually click on the links included in your messages as well as the CTAs (call to action).
  • Email complain rates - this is a metric that measures how many users end up complaining about receiving emails from a particular email campaign.
  • Email engagement time - a metric that determines the amount of time your recipients spend reading your email campaigns.
  • Email unsubscribe rate - a metric that determines at what rate your email recipients unsubscribe from your email campaigns once they receive the messages.

Now, you have to keep in mind that these statistics won’t improve overnight. It can take a long time and a bit of creative endeavor in order to improve them. Take, for example, brand loyalty - it is something that takes a longer amount of time to build and to nurture, so you’ll need to invest time and effort.

Of course, there are some things that you can do right away, like a few tweaks here and there. For example, you can try and make your emails more responsive, which means you can work on how they look and how they open on different devices. Make sure that your emails are consistent in the way they look and how they sound - i.e. the tone, voice, and style of the text that you use to communicate with your users and engage them.

There’s no single recipe for the “right tone”, it depends largely on the type of business you’re in. However, in general, it’s recommended that you personalize your emails, and add a bit of humor and humanity into them.

You can also work on the frequency and the timing of your email campaigns - this is actually pretty important for raising your email engagements. That’s because this metric is highly valued by the ISPs when they filter content through their algorithms.

Try Email Segmentation and Personalization

Segment your emails as a way to better organize your email campaigns.

You can segment your emails according to a set of criteria, like:

  • The region where your users live (part of the wider area of demographics).
  • Age, sex, gender, nationality… (also demographics).
  • Their time zone.
  • Their hobbies and interests, their daily schedules, their activities on your site, and their past purchases.

Email segments will allow you to send the right emails to the right people when they most need them or are most likely to respond to them.

Couple that with personalization, and you can make emails that truly resonate with your clients, that make them feel like they’re being contacted by actual human beings who value their interests and needs.

Use A/B Testing

A/B testing is a great way to see what works and what might not work in your email campaign. It’s a tool that allows you to send several different versions of the same email campaign and see which version works best.

A/B testing allows you to come up with more personalized and user-specific email campaigns, ones that your users will actually look forward to opening. In turn (you already know the drill), you get higher open rates, higher engagement rates, higher sender reputation, and finally - a better sender score.

Make a Checklist for Your Email Campaigns

Make a checklist that will give you a good overview of how your campaigns are constructed. That way, when you compare it with your other email campaigns, you’ll easily know what to change and what not to change, what works, and what doesn’t. Also, checklists will ensure that you haven’t forgotten to include anything vital or important in your email campaigns before you actually send them.

What should your checklist include? Well, for starters:

  • A well-crafted subject line.
  • Equally well-crafted pre-header text.
  • Relevant & proofread content.
  • Accurate links that bring the recipient to the designated address.
  • Well-crafted calls to action (CTAs).

The good news here is that you can also make an automated checklist through your email marketing software/tool, so you save time every time you come up with a new email campaign and decide to send it to your clientele.

Make Sure to Clean Your Email Lists (and Don’t Forget to Use a Double Opt-In)

When you clean your contact lists regularly, you can better prevent sending messages to users who are inactive, and maybe even some whose email addresses have turned into spam traps.

Also, lists that have been cleaned usually have comparatively more engaged users than those that haven’t, and this is even more true with lists that have also been properly segmented.

With good email marketing software, you can track which of your recipients haven’t opened your emails in a while. When you identify them, send them an email that informs them that they’ve been automatically removed from the email list due to inactivity and/or lack of interest.

In order to prevent bot accounts from subscribing to your email campaign, you can also use the double opt-in or the double authentication method where you send a confirmation email to a user once they subscribe to your campaign, where they’ll have to confirm their sign up from their own email address.

But Before You Do Anything, Make Sure to Create Email Campaigns That Truly Matter

What does this mean? Well, first of all, it means that you should adhere to a certain email marketing etiquette. It means not spamming your users, but rather providing them with useful, segmented, timely, and relevant content. It also means allowing them to unsubscribe when they no longer want to see your emails in your inbox. All of this will keep you off email blacklists and it will also keep your sender reputation and sender score high.

So, you need to have a solid concept for your email marketing campaign. You need to include the right metrics, the right processes and workflows, create segmented lists of users, databases of past email campaigns, do some testing to see what works and what doesn’t…

But before you do all this, you have to have a goal in mind. What do you want to achieve with your business? How will you do that? In what timeframe do you want to accomplish it?

That doesn’t mean that you have to come up with the whole email strategy at once. Things will change naturally as the campaign itself develops. But, you do have to have an idea of what you want and how you’re going to go about it, no matter what you end up changing in the future.

That being said, you also have to leave some room for experimentation and testing. Without that, you won’t know where you’re going wrong, and what you’re doing right. So, if you make a mistake here and there, don’t fret! You can always find a way to mend it. It’s just important to be willing to experiment and adapt, to embrace new trends and demands of the market fast, and to open your business up to new possibilities, even if they seem rather unexpected.

Final Thoughts

Email sending reputation is a somewhat complex metric that consists of several other types of reputation and metrics. Still, you can essentially look at it as a way for internet protocols to measure the quality of the sender’s email marketing campaign practices.

Just remember, you’ll be a great email marketer not only when you make remarkable campaigns in terms of design, personalization, and content, but also when you pay attention and follow security protocols that ultimately serve to protect your customers, your readers, and even your business.