On Azure AD Notifications' Privacy Page you can request and collect all the privacy and GDPR related information that Azure AD Notifications is providing.
The privacy policy by is a legal document or statement that discloses how Azure AD Notifications gathers, uses, discloses, and manges their customers' data.
The basis for Azure AD Notifications 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.
Subprocessors are companies that provide a service for Azure AD Notifications and who has or potentially will get access to personal data of their customers.