Is the "email" the PK?
From your code pojo =(RegistrationPojo)session.load(RegistrationPojo.class, email);
I think the email must be the PK, so you needn't check it.
Each time before Hibernate to insert one object, if it found the object's PK is not null, it will take this "insert" as "update" if it finds the exsiting object in the DB.
If you debug into Hibernate's source code, you would find the session.save(registrationPojo) will call the session.saveOrUpdate(registrationPojo);