I came across a situation where an organization had been setup to use RPC/HTTPs “Outlook Anywhere” for some time and all the Outlook 2003 clients seemed to work fine. One user had Outlook 2007 and was unable to connect using this method. In the LAN and through OWA everything worked fine. I tried tons of different solutions online but in the end, the problem was with the configuration in Exchange. I looked over the suggested configuration here:
and I discovered that the RPC ports hadn’t been configured as the article suggests. I used the recommended “RPCnofrontend” tool: http://www.petri.co.il/software/rpcnofrontend.zip and everything worked fine after that.