Sender Score: Everything You Need to Know

Understanding the intricacies of email deliverability and domain reputation is vital in the realm of digital marketing. Sender Score, akin to a report card for your email practices, plays a pivotal role in determining the trustworthiness of your email source. In this article, we delve into the significance of Sender Score, how it is determined, and crucial tips to maintain or enhance your score for effective email marketing.

What is Sender Score?

Sender Score serves as an indicator of the reliability and trustworthiness of an email source. Compiled through a reputable cooperative reputation network, it offers a simplified view of aggregated data from various ISPs, spam filters, and security companies. This data, collected from 60 million mailboxes, mirrors what mailbox providers use to decide whether to accept or reject an email.

Determining Sender Score:

Return Path facilitates the determination of Sender Score through a comprehensive report accessible via their registration page. Scores are calculated as a rolling, 30-day average, representing an IP address’s rank compared to others. Various parameters, including complaints, volume, external reputation, unknown users, rejected emails, and accepted emails, contribute to the score’s evaluation.

Parameters Considered for Sender Score:

Complaints: Evaluation of the complaint rate for your IP address compared to others.

Volume: Proportion of complaints to the total number of messages sent, monitored by the Sender Score Reputation Network.

External Reputation: Comparison of your IP address to others on external blacklists and whitelists.

Unknown Users: Rank of the IP address’s unknown user rate compared to others.

Rejected: Frequency of email bounces compared to other IP addresses.

Accepted: Number of accepted email messages for delivery.

Accepted Rate: Ratio of accepted messages to the number seen.

Unknown User Rate: Ratio of unknown users to the amount of email seen.

Ideal Sender Score:

An ideal Sender Score is considered heavenly at 90. Scores between 50 and 80 indicate room for improvement, while scores below 50 raise concerns. A sender score below 50 necessitates immediate attention and adherence to best practices aligned with email marketing ethics.

Factors Leading to Sender Score Depletion:

Several factors can contribute to a decline in sender reputation and subsequent Sender Score, including complaints, email list hygiene, inconsistent mailing patterns, and more.

Improving an Unsatisfactory Sender Score:

To enhance a less-than-satisfactory Sender Score, consider the following practices:

Maintain Consistent Email Volume:

Set a fixed volume of email sends over a designated time period.

Optimize Email Frequency:

Establish and maintain a consistent interval between email frequencies.

Streamline Opt-Out Processes:

Simplify the opt-out process to encourage ethical removal of email addresses.

Remove Invalid Email Addresses:

After each email segment, eliminate invalid email addresses that cause bounces.

Warm Up Sender Score:

Initiate email sends to loyal customers before reaching out to new leads.

Address Blacklisting Issues:

Understand why blacklisting occurred and improve email marketing methods accordingly.

Monitor SPAM Rate:

Keep the SPAM rate in check, aiming for an acceptable rate of 1 in every 1000 emails.


In the realm of email marketing, Sender Score serves as a crucial metric. Companies dedicated to delivering quality content while avoiding over-emailing typically maintain a positive sender score. Prioritize ethical email practices, and your sender score will reflect your commitment to providing valuable content to recipients.