How to configure Outlook 2003 and Windows 7 Pro to avoid error

With Outlook 2003 and Windows 7 Pro, when I hit the send/receive button, I obtain Internet Security Warning that states "The server you are linked to is utilizing a security certificate that could not be validated. The certificate's CN name does not harmonize the number the passed value. Do you wish to proceed using this server?” I chose yes and the emails show. Please provide advice on how to set up/configure the system to avoid such error again?
