Outlook Express within WIN ME

Hi Guys,
I'm having a little problem with some of the girls in my office. They are setting up there own identities for outlook express so I am unable to track business emails. I am new to the system admin job. The old system network guy left and I've been thrown into the fray. I know that WIN ME is not designed for security and my boss is to tight to spring for new software. I was wondering if anybody could recomend a way of me over coming these security issues in ME and giving me control overthe network. Thanking you guys in advance.

Kim Nelson.
kimnelsonau@yahoo.com.au