your query would need to use to joins, one to join property_enquiries table, and the other to join the enq_correspondence
SELECT *
FROM enquiries
INNER JOIN property_enquiries ON enquiries.enquiry_id = property_enquiries.enquiry_id
INNER JOIN enq_correspondence ON enquiries.enquiry_id = enq_correspondence.enquiry_id
i'm just guessing the the enq_correspondence table has a column named enquiry_id, you will need to adjust accordingly if you use a different name.