Source Server Unable to Authenticate with the Remote Server
If your source server cannot authenticate with the remote server, make sure that the Commerce Server 2009 R2 Staging (CSS) authentication account has at least operator privilege on the project at the remote server. The CSS authentication account that is used to authenticate the receipt of data must be defined on the resident CSS server that receives the data. For more information about CSS authentication accounts, see How Are CSS Authentication Accounts Defined and Managed?