If you have created an account with your personal email address (or social media account) and passed a lesson. You can add an additional email address on your "Edit Account" page. This additional email address (called Associated Email) will allow the employer (work) or educator (school) to see the progress that you have made.
Note: Ideally you would want to create an account with your personal email address, then add your work/school email as an Associated Email. This will allow you to prove you have completed all the courses without having to redo them – if you switch jobs OR graduate school and get a job after (where your employer will want you to prove that you have the integrity to work at that position), you can just add your new email address and BLAM, you are certified!