connect to exchange server 2003 when offline

We have Exchange 2003 installed on the server and outlook 2003 on my laptop.
I connect through the lan when in the office and receive emails ok. I have
set up synchronisation But when offline i need to connect through G3 card.
I've been through all the help but getting a little confused. Can you tell me
the most easiest way to setup. Do i use pop3 imap4 http. all i need is to
connect to the mail server but not sure what to do next.
Thanks