[otrs] How to run periodic mail collection ?

Hello, I'm testing OTRS under Windows XP Pro and first of all, I want to congratulate all the OTRS team for the job !! I'm testing different Open Source ticket systems for a french university in Paris... I have followed the doc section named "Filtering/dispatching by OTRS/PostMaster modules" in order to dispatch incoming mails in my different queues. And that works pretty fine. But : how can I make these mail receptions periodic ? Thanx for any idea / answer. Bertrand