You would need to contact your company's IT department to get the necessary information, assuming they even allow such. They would have to allow POP3 & SMTP or IMAP connections from outside their perimeter to reach the Exchange server. If they do, they can give you the info to configure your mail client.
You might also need to contact your home ISP since many consumer ISPs block outbound SMTP traffic to help fight spambots.
Edited by Andrew, 25 March 2011 - 06:44 PM.