On Proofpoint Email Security and Protection's Privacy Page you can request and collect all the privacy and GDPR related information that Proofpoint Email Security and Protection is providing.
The privacy policy by is a legal document or statement that discloses how Proofpoint Email Security and Protection gathers, uses, discloses, and manges their customers' data.
The basis for Proofpoint sharing, adding, uploading, hosting, accessing or sending personal data out of Europe. Vendors can also add a description of their own impact assessment for data transfers.