When I am in users and computers and click on view and select advanced settings, and then right click on the root and select properties, I do not see Send Asin the premissions list. I have Exchange server 2003 from SBS prem 2003. All loaded with the current SP's. How can I get the Send As to appear?

You can't add send as permissions to the root (I assume you mean domain) itself, or an OU for that matter. Its a user/group/public folder specific permission.