Payslip delivery method

Can you please confirm whether employees can receive their payslips via email while still retaining access to them through the Fourth app (ESS)?

The customer has configured the payslip delivery method as Email, however some employees did not receive their payslips by email. The payslips do remain available within ESS, so we would like to understand whether both delivery methods can operate simultaneously and if there is any reason why the email delivery may not have been successful.