You should research solutions like:
Is there a way to receive and synchronize e-mail on multiple computers without going through an exchange server? I regularly use three machines: a desktop, a notebook, and a "netbook." When my e-mail was routed through an exchange server I could log on from any computer and all messages would be accessible. Now I don't have that luxury and am using only the notebook for e-mail to avoid having messages spread over three machines. I'm using Outlook 2007 as the e-mail program. The OS is windows 7. Outlook 2007 is available on the other machines, which are running XP.