CDO Application Fails With E_FAIL (80004005) Error Message When It Accesses Items in a Public Folder. After moving Public folders from Exchange 2007 CCR cluster to Exchange 2010 one of our internal application starting failing. I don't have much to go on since the person that developed it in no longer with the company. All I know is the app is using Interop.MAPI.Dll to take items from a public folder and run it through the app and put it back in a different public folder. When we moved to a new 2010 Public Folder server the app team said they are getting this error "E_FAIL (80004005)". The app team is using the new PF server name but they still get this error. Please let me know if anyone can help. Sorry for the lack of information. george

Hi, Was/Is MAPI/CDO installed on your CCR Cluster Nodes? If so, it could be that it was used for this PF Internal Application and needs to be installed on Exchange 2010 too for it work. Microsoft Exchange Server MAPI Client and Collaboration Data Objects 1.2.1 http://www.microsoft.com/en-us/download/details.aspx?id=6248Martina Miskovic