If we mark an email as "Invalid" and you know it is "Valid", we would like to know about that. If you get an unusually high bounce rate off emails that we said were valid, like over 2%, for emails we’ve marked “valid”, we will like to know about that, also.
Please send us an email at: email@example.com with the SMTP logs. It's very important that we see the actual SMTP Reply, because emails can bounce from many different reasons, including the content of the email you are sending.
We are always trying to improve our algorithms and we believe we offer the best validation, abuse and spam trap detection, and data append features on the market.