Deliverability or Inbox Placement Rate

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Inbox Placement Rates (IPR) are between 0% to 100%; once you finish the equation, turn your answer to a percentage by multiplying by 100.

Tips for interpreting Inbox Placement Rates:

Inbox Placement Rates are meant to show the percentage (or fraction) of emails that were delivered to the inbox rather than the spam or junk folder — however true inbox placement, also referred to as deliverability, is very hard (if not impossible) to measure and report on accurately. This is because, unlike with Delivery Rates, mailbox providers (MBPs) do not provide any feedback that tells a sender if a message was delivered to the inbox or to the spam folder.

To gauge inbox placement, email senders must rely on panel and pixel-based cues within their email metrics (such as open rates, click rates, unsubscribes, and marked as spam reports) and the seed testing and panel data that is available through 3rd party deliverability monitoring services. Some email service providers (ESPs) offer an inbox placement rate, which is typically created in the same manner as / or is integrated with 3rd party deliverability monitoring services.

In general, the HIGHER the inbox placement rate, the better. However, high inbox placement rates don’t fully tell the story of the success of an email, nor do low inbox rates mean an email was a complete failure. 

While seed testing can give an indication of inbox placement, MBPs confirmed long ago that they could clearly tell the difference between a test account and an email address owned and managed by an actual human user. When you are looking at Inbox Placement Rates, remember that the percentage of emails being reported as delivered to the inbox can be inaccurate because it is based on a form of seed testing, panel data, or an engagement-metrics-based calculation. Your inbox placement rate can vary greatly from your actual inbox placement. It can also vary greatly from one ESP or 3rd party provider to another because of the technology being used to provide the scoring.

Verizon Media Group (VMG) began offering access to an Email Deliverability Placement Feed in February 2020. However, access to the data comes at a cost. The data is also limited to the VMG network (including Yahoo, AOL, and Verizon domains, among others), leaving email senders to still question their true inbox placement rates with other MBPs.

When you are looking at Inbox Placement Rates, remember that the percentage of emails being reported as delivered to the inbox can be inaccurate because it is based on a form of seed testing, panel data, or an engagement-metrics-based calculation. Your inbox placement rate can vary greatly from your actual inbox placement. It can also vary greatly from one ESP or 3rd party provider to another because of the technology being used to provide the scoring.

Inbox placement rates are best viewed as a trendline over time. They should always be taken with a grain of salt and viewed alongside more finite metrics. Avoid only looking at inbox placement rates when you are evaluating a single email. And be very cautious when comparing inbox placement rates from different 3rd party providers or ESPs. 

See our other articles for examples of metrics that are more accurately measurable, such as delivery and click rates.

In summary, inbox placement rates can be used to:

  • Have a general idea of whether emails are making it to the inbox or not
  • Identify problematic trends with approximate inbox placement over time

Related Links:

Curious about how inbox placement rates are calculated? Check out Email Experts Series: Ways to Monitor Inbox Placement and Email Deliverability Crash Course: What Every Emailer Should Know

Interested in learning more about the accuracy and effectiveness of seed testing? Check out Email Seed Testing: Truth vs. Myth

Not sure if Inbox Placement Rates are right for you? There are some that would argue that they are misleading. To learn more, check out these articles: