push only new emails pop3

Hi,

Is there any setting in exchange that only pushes new email to its client?

In my case, the client is VB.net service. The functionality of this service is to connect to exchange pop3 account and process emails in the inbox.

The problem I have that I always get all emails. I don't only receive only new emails.

That's why I m looking some setting on exchange to push only new emails.

Any suggestions.

Thanks,