From: DeskNow Knowledge Base
http://www.desknow.com/kb/

My spam mail is being downloaded to my Outlook pop3 client. Why?
http://www.desknow.com/kb/idx/4/150/article/

By default, DeskNow is set to send all received mail - including spam - to pop3 clients.

The reason why it is doing it is that it is conservative by default - there may be false positives in your spam folder, and we don't want you to miss those.


Possible solutions:
1. consider using IMAP instead. It's a better protocol ( http://www.desknow.com/kb/idx/0/028/article/ )

2. disable the option in Administration/Antispam/POP3 . In this case, pay attention to the daily spam report sent by DeskNow to check for legitimate messages classified as spam.