Hi dock,
You can connect to the MSN account with a pop3 connection from the iPhone.
Set your primary computer to download email and the secondary to leave a copy of messages on the server.
Hotmail recently opened up pop3 access for all accounts. Here are the general directions for configuring pop3 access to your account :
http://www.emailquestions.com/hotmail/227-do-i-configure-my-hotmail-msn-email-account-work-pop3.html
Welcome to Email Questions! -Raymond