This issue occurs if either of the following conditions is true:
- The MAPI client computer is running out of physical memory.
- The MAPI client computer is running out of virtual memory.
Typically, this error occurs when you use LoadSim to simulate the performance load of a MAPI client computer that is used by more than 1000 MAPI users.
The error that is mentioned in the "Symptoms" section is generated by LoadSim. This error refers to the memory configuration on the client computer. This error does not refer to the memory configuration on the server that is running Exchange Server 2003.