Blackberry Torch read emails don’t show up in Outlook

My Blackbery torch has my POP email account on it. If I open an email on my BB first, it will not show up in my desktop inbox in Outlook. Why does that happen and how can I prevent it?

My Blackbery torch has my POP email account on it. If I open an email on my BB first, it will not show up in my desktop inbox in Outlook. Why does that happen and how can I prevent it?