Q: What do the “Latency” and “RPC Calls Succeeded” mean in the Exchange 2003 ESM? To see this choose a mailbox store -> Logons -> View -> Add/Remove Columns.
A: These calls are derived from the Client-side data reported by Outlook 2003 if enabled (see Gerod Serafin's previous post for more information on this). Exchange aggregates this information per LOGON and the Outlook client will aggregate this per connection. So, if you disconnected from the network, Outlook would include all information from multiple networks, but Exchange would only contain the average of this LOGON. The ESM measures this latency on Milliseconds and includes the network latency as well as any server processing latency. With a good LAN and a healthy server this should average less than 100 msecs. This can be much larger when a client is connecting over large network distances.
“RPC Calls Succeeded” is just the raw count of of RPC calls that LOGON has recorded.