October 9, 2023

Email Sender Reputation Guide: How to Check and Improve Your Email Sender Score

Reading time about 13 min

Mailbox providers like Gmail use your IP reputation — also known as email sender reputation, email reputation, or sender score — to determine whether or not your email should be delivered to the inbox. To make sure your emails don’t end up in your contacts’ spam folders, the first step is avoiding common mistakes that damage the reputation of your sending IP address.

Experienced email marketers know that it’s not just about getting the job done. It’s about getting the job done right the first time. You don’t want to invest time crafting a beautiful, well-designed email campaign, hit send, and then have it land in the spam folder of your subscribers. This won’t generate revenue and will make you do double the work.

If you’re struggling with these issues, work on improving your email deliverability, or the ability of your emails to reach the inbox. One of the main factors in determining email deliverability is the sender reputation of the IP address you use to send emails.

How email providers calculate sender reputation

Email providers use algorithms to monitor the behavior and assess the risk potential of every IP address delivering messages to their network. To evaluate sender reputation, these programs take factors and metrics into account such as:

  • Quality of contacts to whom that IP address is sending messages
  • Level of engagement recipients show for emails from that IP address (open rate, click rate, unsubscribe rate, complaint rate, etc.)
  • Sending volume trends
  • Quality of email content being sent by that IP address
  • Presence of email domain authentication checks such as SPF, DKIM, DMARC

Those are just a few examples of the signals email inbox providers look at when determining sender reputation and filtering for spam. Needless to say, you want to make sure the IP address you use to send emails has a good sender reputation.

One way to ensure a good sender reputation is to use a dedicated email marketing service like Brevo. We have a rigorous anti-spam policy in place and monitor sender reputation automatically to limit any potential deliverability issues.

Try Brevo for free >>

2 Easy ways to check your email sending IP reputation

If you’re having deliverability issues, run an email reputation check first. It’s possible that you unknowingly sent emails in a way that is viewed as spammy by some email inbox providers. Or worse, maybe your IP has been put on an email blacklist.

Whatever the case, start by benchmarking where you are now. There are not many publicly available scores, but the tools below are a good starting point to measure your IP sender reputation.

1. Sender Score from Return Path

An image of the Senderscore homepage for checking email sender reputation.

Return Path has come up with an email sender reputation metric called “sender score.” Your sender score is expressed as a number between 0 and 100, the higher the better.

Much like a credit score, the sender score of your IP address can be easy to damage and tough to improve. 

To put this in perspective, Return Path put together a 2019 Sender Score benchmark report, showing deliverability rates. Small changes in your score make big differences in your email deliverability. A score that drops from 83 down to 70 can see the delivery rate decreasing by approximately 20%. This will lead to a huge loss of revenue.

To get a free assessment of your current Sender Score, just go over to SenderScore.org and plug in your IP address.

Just keep in mind that it’s just one company’s metric and not an industry standard. A lower sender score will have an impact on deliverability, but it’s not the sole indicator.

Email services like Brevo have dedicated teams to maintain sender reputation and ensure deliverability for its clients. Thus, if you follow the best practices outlined later in this article, and use such a service, your email will land in the inbox every time.

2. Talos IP and Domain Reputation Center from Cisco

Talos Intelligence Group is part of Cisco and provides network security solutions for businesses. Talos lets you look up your sender reputation by IP address for free on their website.

The results show you the IP reputation score for both web traffic and email of the IP address you entered. Scores can be “Good,” “Neutral,” or “Poor.” There’s also more detailed information about sending volume history and related sender IPs.

7 Common mistakes hurting your sender reputation

Once you’ve checked your sender reputation, you’ll know where your reputation stands with the email inbox providers.

If your IP sender reputation is lower than you hoped, it could be that you’re unintentionally sending the wrong signals to email providers.

To help you avoid this moving forward, here are 7 common ways senders damage their sender reputation without even realizing it.

1. Collecting misspelled email addresses

It’s so easy to collect invalid email addresses. On average 80% of invalid contact data is simply due to human error. Especially when people type on mobile devices.

So how does this impact your email sender reputation?

Hard bounces make up one of the largest portions of your sender reputation. If the email address you collected isn’t legit, email delivery is impossible, resulting in a hard bounce. Most email service providers will not tolerate a high hard bounce rate because you’re damaging their IP reputation and will suspend your account, bringing an end to your marketing campaigns.

Read more: 11 Easy Ways to Decrease Your Email Bounce Rate

As a best practice, always set up a double opt-in authentication for new subscribers. Anyone who signs up receives an email asking them to click a link to confirm their subscription. This validation prevents misspelled addresses from being added to your email list.

You can also use a solution for real-time email verification to check the email address before you accept it into your marketing funnel. This way if the user has made an accidental typo they’ll see an error message and have a chance to correct their mistake.

2. Using purchased email lists

Businesses often turn to data suppliers for new leads and new customers.

It sounds like an ‘easy choice’ because you can quickly grow your list. However, the bad news is that you’re not growing your list organically. Working with data brokers will not help you improve your engagement rates and you shouldn’t buy email lists.

To have good email deliverability and improve your sender reputation you need to have subscribers engage with your emails. This means they need to open and click the messages you send, showing your emails have a high click-through rate.

If you send to contacts you’ve acquired through a list broker, they didn’t sign up willingly. What makes you think they’re going to engage? Open rates will most likely be abysmal and unsubscribe rates sky-high. And you run a very high risk of getting marked as spam.

Spam complaints are a big part of reducing your sender reputation. Each complaint you get is like sending a message directly to the internet service providers (ISPs) that their users do not trust your company. If you get too many spam complaints with a specific ISP, they can choose to just push all of your marketing emails directly to the spam folder. Imagine if all your Yahoo recipients never see your message from an email blast because Yahoo has decided to put you in the spam folder.

Further reading: Deliverability 101: How do email spam filters work?

3. Not cleaning your email list

Why are you keeping old data on your email list? It’s only costing you more money to keep uninterested contacts there. (Not with Brevo, as we offer unlimited contact storage for free, but with other email services for sure.)

As an email marketer, it’s your responsibility to regularly remove unengaged users from your list. Users who are not opening or clicking on your content damage your sender reputation.

For example, if a user has abandoned their email account, they aren’t opening your emails. This will later create a hard bounce. 

They also might not engage with your email content because they already moved you into the spam folder without your knowledge.

Cleaning your list is something you should be doing on a quarterly basis (if not more frequently). If you don’t feel ready to take the leap and delete a good portion of your contacts, learn how to do email list segmentation to get similar benefits.

4. Not using proper domain authentication

ISPs need to know that you are indeed you to avoid fake senders posing as you and spamming their users. Keep your emails from being marked as spam with SPF, DKIM, and DMARC authentication protocols.

These sound like big, complicated acronyms, but they just prove your IP address is credible and your emails are genuine. They can easily be set up directly in your email service provider like Brevo.

5. Sending poor-quality content

Never compromise quality for quantity. If you slap together a poorly created email campaign, users are much more likely to complain and unsubscribe. You know now that spam complaints damage your sender reputation, and poor content gives them a reason to complain.

Instead, create high-quality email content with the following tips:

6. Sending emails inconsistently

This is often overlooked by email marketers, but your email frequency matters when it comes to calculating your sender reputation. 

You need some balance when creating your email campaign calendar. Email too often and you risk annoying your users and generating spam complaints. Email too little and you miss out on sales opportunities.

The bottom line is, if you don’t have a consistent schedule and email random days and times of the week instead, your users may lose interest. A study by Return Path found that read rates decline as send frequency increases.

send frequency affects email sender score

As a rule of thumb, it’s best to stay focused. Set clear expectations with new subscribers up front. Say how many times per week they should expect to hear from you right on the signup form. Here’s a study on the best time to send emails by industry.

Another thing to keep in mind is how your subscriber list is growing. A quickly growing list or adding users in bulk to your ESP doesn’t look good. It gives the appearance that you’re purchasing data and not following best practices.

7. Keeping spam traps on your email list

Spam traps threaten the good reputation of your email campaign. One rotten apple can bring down the whole tree.

The problem with email traps is they can directly lead to getting blacklisted. Therefore, many marketers tend to jump ship from email platform to email platform because the black listings prevent their whole campaign from being delivered.

There are two main types of email traps. Pristine traps are email addresses created by ESPs or blacklist organizers posted across the web. They get into your list if they were “scraped” or “harvested”. You might not directly be scraping data from the web, but you never know if a data supplier has used these techniques (hint: they most probably are).

The other type of trap is the recycled spam trap. These are email addresses that were once real but have been abandoned by the user. The ESP deactivates the account causing hard bounces for you, so you should remove the user from your list.

After the email address is inactive, the ESP reactivates the account many months later. If that account still receives emails from you, you will be blacklisted for not following best practices.

To avoid falling for spam traps, use double opt-in signup forms for new subscribers. 

To get rid of spam traps, monitor addresses for inactivity. If you notice a contact who hasn’t engaged with your marketing emails in six months, send them a reactivation email. Still no answer? Get rid of this contact!

Boost your sender reputation

Maintaining a good email sender reputation means your marketing campaigns are more likely to make it to your subscribers, get opened, and earn revenue — pretty important stuff! 

In sum, here’s what you need to do to improve that sender reputation:

  • Clean your list by regularly removing unengaged contacts
  • Use double opt-in confirmation and/or an email verification tool to prevent misspelled addresses from winding up on your list
  • Never buy contacts – always use lists that are 100% opt-in
  • Stick to your promised frequency so subscribers know how many emails to expect – this reduces complaints
  • Avoid spam trigger words and poor content – these will get flagged by spam filters
  • Use authentication checks
  • Create high-quality content that brings value to your subscribers

Improve your email sender reputation with Brevo

Easy list segmentation and cleanup automation, A/B testing, beautiful email templates and double opt-in available.

Open my free Brevo account now >>

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