Sender and Delivery Rating

Your sender rating and email delivery ratings provide quantitative insight into the quality of your lists and emails and can be effected by email complaints.

Your sender rating is driven by the level of contact engagement (opens, clicks, conversions) your sent emails that were received, complaints your emails receive from ISP Feedback Loop, and internal measurements that we use to help you optimize your deliverability. Your sender rating is used to monitor the health of your account and to protect you from repeatedly sending to bad segments, lists, or contacts. The delivery rating is calculated on a per email delivery basis, rather than on the total email deliveries you have sent. The email delivery rating is driven by complaints an email delivery receives from ISP feedback loops, the level of contact engagement (opens, clicks, conversions) the email has, and our internal measurement thresholds. Your email delivery ratings effects the sender rating for your account.

To make things simple, we came up with a 10 point scale for sender rating. If your sender rating is:

  • 6 or above then there is no negative impact on your account or your ability to send email.
  • 5 or below then your bulk email deliveries will be throttled over a period of 10 hours.

If your email sender rating dips to an unacceptable level, you will receive a notification from Bronto's Deliverability Team and any email messages you send are automatically throttled over a 10 hour period. Throttling slows your email delivery speed, and thus spreads your email deliveries out over time. For example, instead of sending your email message to 100K contacts as quickly as possible, throttling will spread the delivery over a period of 8 hours. To stop the throttling, you will need to raise your sender rating back to a 6 or higher.

The sender rating is calculated based on a rolling, 30-day period. After 30 days events are dropped from the calculation.

The deliverability rate represents the average number of sent emails that are successfully delivered to your contacts. This metric will be blank if there were no deliveries the previous day.

Keeping an eye on your email delivery ratings is a good way to help keep your email sender rating high. It is important to remember that the number of email complaints you receive is tied to your email deliverability; a high numbers of email complaints, coupled with a low level of contact engagement, will negatively affects your email deliverability. Email complaints occur when an unsubscribed user elects to fill out a Complaint Webform or when one of your contacts submits an unsolicited email complaint via an inbound email to our abuse team or through an ISP feedback loop.
Note: ISP feedback loops are services provided by some ISPs which allow us to receive notices when a contact clicks a Spam or Unsubscribe button in their email client.

We maintain a history of all email complaints in all accounts and use internal measurements to calculate each account's email sender rating. Accounts that generate few email complaints will encounter few email delivery problems. Conversely, accounts that generate numerous email complaints will see their email deliverability negatively affected. Upon receiving an email complaint, Bronto automatically unsubscribes the contact in your account. We will also log the event in our customer tracking system.

Tip: Many major ISPs track a sender's reputation based on the number of unsolicited email complaints that they generate over a certain period of time. The worse your sender reputation is with ISPs, the more likely you are to have a low sender rating in the application. Spreading your email delivery over time can help mitigate the impact of this issue, help ensure optimal deliverability, and mitigate traffic spikes on your website. For example, 20 unsolicited email complaints received over 8 hours, though certainly undesirable, will be a softer blow to your sender reputation and sender rating than the same 20 complaints received over 15 minutes.

With this in mind, even if you have a high sender rating, you still need to look for ways to reduce your email complaints and increase contact engagement. For example, you may have an email sender rating of 10, and while this is a good thing, it does not necessarily mean you are performing perfectly. Rather, it means that you are doing well in comparison to other marketers using the application, and that your emails are generally performing well according to our internal measurement thresholds. You may still have some email complaints, and there is always room to improve contact engagement. We suggest reviewing ways to decrease email complaints and increase contact engagement, rather than taking your email sender rating as absolute and becoming complacent with your current practices. Always striving to improve your email marketing campaigns is essential!

If you notice that your sender rating has dropped, you may be able to pinpoint deliveries with low delivery ratings as contributors to your low sender rating. Always look for ways to improve your email delivery rating, even when your delivery rating is high. We suggest monitoring the email complaints an email delivery receives and continually trying to reduce that number. The best place to track complaints is on the Deliverability tab of a Delivery Report.

Additionally, finding ways to increase contact engagement (opens, clicks, conversions) will have a positive impact on your email delivery ratings.

By tracking email complaints and enforcing restrictions on accounts with excessive email complaints, we are able to protect the overall email deliverability of our customers and the inboxes of our contacts from any single account that violates our terms of service by sending unsolicited email.