Synchonization of user and people email

Hi all

Is there a workflow or a concurrent program that synchronize the email of the employee with the email in the user form. The firstime we link a user with an employee, the email in the user form is automatically updated. But we have a few case when the HR dept. change the e-mail in the people form (People, Office Details Tab). If they dont go change it in the user form, they never get synch. So we are wondering if ther is a concurrent program that do it or a workflow program.

Thanks!