Application Development Software

Hello.
I have tested SpamAssassin with sendmail and everything works.
Now I am testing in Sun One Messaging 5.2 p2 in Solaris 8 with SpamAssassin 3.0.4, I was reading some posts and I have some questions because
I don�t like to reject messages, only mark them like "spam" or not.

1-With Messaging 5.2 is only possible send messages detected like spam to "Spam" folder in the web GUI?
2-Is possible this in POP clients?
3-I supossed it doesn�t work in POP clients, like is not possible mark the messages (for me mark a message is add to
the subject the word **SPAM**) , how can I know in my POP clients if the message is spam or not?

Thanks a lot