Spam and duplications

We are using Contact Form 7 in conjunction with Flamingo. We’ve deactivated our anti-spam plugin because too many legitimate form submissions were being flagged as spam. We still have legitimate submissions showing up on Flamingo’s spam list. And we have many submissions duplicated on both Flamingo’s inbox and spam lists. We’ve already reached out to Flamingo and haven’t gotten a response. Is there anything we can do to prevent duplications and prevent submissions from being flagged as spam?