Ladies,
I have just done the Pablo machine at Nice airport and also stopped at the Custom office (right next to the machines and since there was no line... I stopped by and asked the officer if I did everything correctly. He was very pleasant and politely helped me check in his computer, which he could already see the forms I scanned, and told me there is NO NEED to send the forms as he can see in the system all the data (what I bought, payment etc)!
So he told me to just keep the forms for my record and check/track online my tax return progress!
So ladies no more mailing the forms!
Thank you this is very helpful info. That being said, I'll probably continue to mail forms as a backup as long as H keeps providing envelopes and forms. While Pablo/France customs can see the data there is still some kind of integration to Global Blue since they are issuing the refund. I'm assuming it's a fully automated process but on the off chance something goes off it might be taken care of faster if Global Blue has the form in its possession.