In December 2018, SparkPost launched its first version of Recipient Validation. By August 2019, we made improvements with a stronger algorithm to identify undeliverable and risky email addresses based upon hard bounces in our email data footprint. Now to ring in the new decade, we are introducing some significant improvements to bring you the most powerful and truly data-driven Recipient Validation tool on the market!

 SparkPost’s Data Footprint Works Harder with Delivery and Engagement Events

SparkPost now leverages delivery and engagement (clicks and open) events, in addition to hard bounce events to train our validation algorithm, bringing you one of the most powerful data-driven email validation tools on the market. The inclusion of these additional hundreds of millions of events gives you confidence in email addresses that we categorize as valid – our data indicates we have seen deliveries and/or active engagement associated with the email address and do not have data suggesting that it is an invalid email address for any reason.

New Typo Result Category: Make it Easy and Simple to Identify Potentially Misspelled Domains

Working with customer feedback, we improved how we present  misspelled domains as an additional attribute for valid, risky, and undeliverable email addresses to make it easier to filter out and quickly take action.  To make it even easier, we pulled out the “did_you_mean” typo domain attribute and made it a top-level category result, giving you a clearer and cleaner split of your email list to identify potentially misspelled email addresses. No more drilling down to figure out which email addresses were typed incorrectly!

New Neutral Result Category: Straightforward and Honest Email Validation based on Data

Before we were able to leverage delivery and engagement events, our category result valid was comprised of email addresses we had either (1) never seen a hard bounce for, (2) an email that may have hard bounced in the past but had not had any subsequent hard bounces for a significant amount of time, or (3) a default status for email addresses we had no hard bounce data for. We’ve quickly moved away from this model to give you clearer and upfront validations without any ambiguity. Email addresses that we categorize as neutral mean that they:

  • Have been checked for proper syntax, proper domain, existing MX record
  • Still provide a check against role-based domains, free domains, and disposable domains 
  • Have not had a hard bounce in our data footprint, but also have not had any delivery and/or engagement events in our data footprint 

We cannot confidently tell you that email addresses categorized as neutral  are completely valid, as we have not seen a delivery and/or engagement event. The neutral result helps you make better informed data-driven decisions when dealing with recipient email addresses. Our best recommendation for neutral email addresses: If you are risk-tolerant and can afford to send to some potentially undeliverable email addresses, try sending to neutral as there is a potential low risk. If you are completely risk-averse and must only send to completely valid email addresses, avoid sending to neutral for the time being. 

How to Get Started with Recipient Validation

As more of our beloved customers test and integrate Recipient Validation into their email sending, our team is committed to continuing our research and development to improve our ability to identify email addresses accurately so you can be confident in your sending, instead of relying on outdated and inaccurate checks. We always welcome and super appreciate feedback as it helps to shape and inform our roadmap decisions!

Jump into the SparkPost app (EU) to validate your email address lists now! Dig into the documentation and start validating email addresses in real-time with our real-time API!

Happy New Year!

— Isaac Kim, Group Product Manager


❤ Special thanks to Sailakshmi Pisupati, Scott McCammon, Nupur Kulkarni, Doug Remsberg, Matt Gray, Ian Scherer, Nathan Durant, Chris Iwaskiw, George  Schlossnagle, Nick Lemmon, Lynn Murphy, Aubrey Altmann, Paul Koprowski, Aaron Sunhao Shen, Jason Soni, Angelica Garcia and to everyone at SparkPost involved in making this next iteration of Recipient Validation so awesome!