I recently started at a very large company who is in the beginning phase of migrating 60 global Exchange 5.5 servers to Exchange 2003 – there are over 15k users. This company is also going to be merging a smaller company they purchased this year into the environment at the same time the global migration is going on. This is where I need to reach out and ask for some help – if there are some experts on this list or anyone who can help me with some ideas, suggestions or even a quick how-to/step by step list that would be great. I'll list out the details (that I know) below. Headquarters: - Main hub, forest location with multiple subdomains - Currently Mixed mode environment - lots of 5.5 servers left to be migrated to 2003. NEW Satellite office to be brought in: - Currently on Exchange 5.5 which is hosted in their local domain - Users in this new sat. office log into a new windows 2003 domain here. I believe there is a trust setup in the forest so that they can log into the new domain however still access their email on the E5.5server in their old local domain. - Goal is to get them moved to Exchange 2003 in our environment so that calendar/free-busy info can be shared globally. My thoughts are to: - install an Ex2k3 server in our Organization then use the Exchange migration wizard to move the data cross site (cross country really) to here and be done. However I know there's a lot more to it than that. Can anyone help me make a stepbystep plan to do so? I appreciate totally any help you can provide. Thanks!