Hello, At one of our customers we installed Exchange2007 SP3 & RU3v2 on all our CAS/HUB servers and 6 CCR Mailbox-cluster servers. Since the installation we have the following problem on two of the Mailbox-clusterservers: 1. Messages to the mailbox-servers are delayed on the HUB-servers. 2. When performing a switchover on the cluster we receive the error: "Moving Clustered Mailbox server failed because of a transient communication error with the windows cluster service". We only have both problems on the preferred active node of the mailbox cluster servers. On the "passive" node the Mailboxserver is performing without issues. Steps we already took: Reinstall Servicepack 3 and Rollup3v2, Run ExBpa: no issues found. Does anyone have an idea what the cause could be for this problem?

Hi, If you are using forefront on these server try to updated to the latest services pack & the check if the issue persist or not, do let us know if that didn't help. Ripu Daman Mina | MCSE 2003 & MCSA Messaging | MCC

Hi SietseB, Any udpate for your issue? Regards! GavinPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.