Outlook Express Database (DBX)
Outlook Express uses the Outlook Express Database (DBX) database to store emails, folders, etc.
DBX files of Outlook Express 5.0 (OE5) and later start with hexadecimal: 0xcf 0xad 0x12 0xfe. For now it is assumed that this is the file signature.
In OE the DBX files are used to store email per top folder (e.g. Inbox, Outbox) and the folder-hierarchy.