REGEXP_LIKE to validate email id.

DECLARE

email VARCHAR2(50) := 'user@example.com';

BEGIN IF NOT REGEXP_LIKE(email, '^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$') THEN raise_application_error(-20000, 'Invalid email'); END IF; END;