Hello,I've got a question concerning the Uprade-Order for Exchange 2007: To fix a bug, we have to Upgrade our Mailbox-Servers to SP1. For some reasons it's hard for us to also upgrade the CASs and Hub-Servers in a short period.So, my question: Is running a SP1 Mailbox-Cluster with RTM CASs and Hub-Servers supported? Anyone ever installed this? Or do we have to Upgrade CAS and Hub before the Mailbox-Cluster?Thanks for your help!Filip

Hi,i've found a part of the answer myself:"We recommend that you upgrade your servers that are running the Mailbox server role after you upgrade your servers that are running the Client Access, Unified Messaging, Hub Transport, or Edge Transport server roles."http://download.microsoft.com/download/5/e/6/5e672458-592a-44a2-b489-11cec19d3c82/RelNotes.htmThe only question now is: is it only recommended, or will it really not work?Filipp