Você pode usar a função analítica ROW_NUMBER():
SELECT *
FROM (
SELECT a.*, ROW_NUMBER() OVER(PARTITION BY LName, FName ORDER BY Email DESC) rnk
FROM <YOUR_TABLE> a
) a
WHERE RNK = 1
SELECT *
FROM (
SELECT a.*, ROW_NUMBER() OVER(PARTITION BY LName, FName ORDER BY Email DESC) rnk
FROM <YOUR_TABLE> a
) a
WHERE RNK = 1