MySql Query - find records from one table which don't exist in another

MySql Query - find records from one table which don't exist in another:-

Table 1:-

social_auth_email

email varchar(75)

Table 2 :-

 studentdetail

email varchar(75)

Then below query for find non duplicate records :-

SELECT sa.email  FROM   social_auth_email as sa LEFT OUTER JOIN studentdetail as htc   ON (sa.email=htc.email)   WHERE htc.email IS NULL