Exchange 2007 SP2. All roles on one physical server. W2K3 domain controllers. W2K3 FFL and DFL. I've seen this discussed here with no apparent resolution: http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/a5e2d28e-947b-4ed1-b90c-2e761711372c The error messages reads like this: Could not read the Security Descriptor from the Exchange Server object with guid={xxxxxxxxxxxxxxx}. As a result the Proxy Address Calculation RPC interface will not be available on the local Exchange Server." - Exchange BPA shows no errors. - Exchange server and our two DCs are on same network switch so replication should not be an issue. - Tests such as DCDIAG and NETDIAG show no errors either. - Exchange functions correctly. In my case, the error occurs about once a month. So not very often. So, is this the sign of something that should be examined more closely or can I ignore it?

Hi, This is very common SCOM aletrs and generate when you reboot your DC for patch or maintenace With error "This server will not be able to calculate proxy addresses for new mailboxes added to the server", very common for CCR clutser. You can simply ignore this alerts ! http://technet.microsoft.com/en-us/library/bb218824(EXCHG.80).aspx Anil

When I "reboot [my] DC for patch or maintenance". Yes, I checked my logs and indeed, that is about the time I rebooted one of the DCs. Add the fact that this happens about once a month... Makes sense to me.