MS Exchange 2003 on Server 2003 SBS Question……..

I’m having an issue where a User who has a company email account and a comcast account that routes to the same account, is getting undeliverable messages. I can’t see the exact message (just able to use the search tool to see it in her box and who its from). Just wondering if there is a way to actually view a User’s email from Exchange….. Any help is appreciated….