Office 2k3 - Messaging interface returned unknown error when I reply all or print a message

I am using Windows Vista Ultimate. It came with Microsoft Office 2007 in it. I was not able to understand the interface so I removed it and installed Office 2003. I thought that would be more better. When I try to send a email directly from the office application I am getting a error on the screen. The error is " Messaging Interface has returned an unknown error. If the problem persists restart outlook." This is a constant error. I cannot find any solution for this.

It looks some kind of problem with email configuration. In Start search box type Mail. Click on the application that appear first and in that add the mail account in it. If it is available then try to remove and reconfigure the same back again. This would be more helpful and better.