Return Path's New Year Community Challenge: Week 6

This week’s email best practice is: Know Your Sender Score

Wow, was that a quick six weeks or what? We are in the home stretch now …

In this final week the focus is on figuring out if all our hard work is paying off. Our six-week program was focused on practices that will improve your email sender reputation. This improved reputation will lead to improved deliverability.

So how do you know if it’s working?

One quick metric that you can use to assess your reputation right now is your Sender Score. The Sender Score is generated from the Return Path reputation data network which aggregates information from 85 million mailboxes at a variety of ISPs, spam filtering and security companies. The better your Sender Score, the better your email sender reputation. The score is on a scale of 0 to 100, where 0 is the worst, and 100 is the best possible score.

The information incorporated into the Sender Score includes:

  • Complaints: We measure how often subscribers report your messages as spam.
  • Volume: Volume is not in itself good or bad, but is an important part of the overall reputation algorithm: for example, an IP address which sends 100 messages and receives 99 complaints is problematic, while an IP address which sends 100,000 messages and receives 99 complaints is probably okay.
  • External Reputation: We monitor the inclusion of IP addresses on a variety of external blacklists and whitelists.
  • Unknown Users: Unknown user rates are taken directly from incoming SMTP logs of participating ISPs, tracking how often an IP address attempts to send a message to an address which does not exist.
  • Rejected: We measure how often messages are rejected (bounced due to some policy reason, usually spam filtering or blacklisting) compared to other IP addresses seen in the Sender Score Reputation Network.

What is a “good” Sender Score? At a basic level, high is good and low is bad. We have found that the best email senders regularly maintain a Sender Score above 80. And anything below 30 should be cause for alarm. The reputation issues that are giving you a score that low are almost certainly causing blocking of your email. But there is no absolute rule that a certain score guarantees either delivery to the inbox or blocking from the inbox. Every receiver uses the reputation factors that make up the Sender Score in a different way. For more insight on this, check out this recent blog post by Alex Rubin, our VP of receiver services, about how Comcast uses the Sender Score to determine feedback loop inclusion. Also be sure to check out our Reputation Benchmark Report which shows that, on average, servers with higher Sender Scores enjoy higher delivered rates.

How often should you check your Sender Score? Your score will fluctuate based on your mailing practices, so you should check it regularly so you can spot a possible problem before it escalates. How regularly depends on your mailing frequency – the more often you mail the more often you should check.

You can learn your Sender Score right now by entering your IP or domain in the form found at We make this reputation information free for anyone in the email community to access.

Community Challenge Re-Cap
We hope you have enjoyed our New Year Community Challenge. If you missed any of the weekly posts you can catch up now. Meanwhile keep your eyes on your inbox – anyone who signed up for the Challenge will be receiving a Community Challenge Wrap-Up Report. It includes all the great information from the series, plus community quotes, quick tips and more. All in a convenient, easy-to-print and share format. Don’t miss out!

Week 1: Send a welcome message
Week 2: Keep your list clean
Week 3: Authenticate
Week 4: Get your infrastructure in order
Week 5: Send more relevant messages
Week 6: Know your Sender Score

By the way, if you never officially signed up for the Challenge, it’s not too late. Sign up now to get your copy of the 2009 Return Path Community Challenge Wrap-Up Report.

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