MAPIDBG.INI [Local Heap Failures] Section

The entries in this section control features in the MAPI memory allocator that generate artificial allocation failures to test how other components handle out of memory conditions.

AllocsToFirstFailure = number of allocations
This entry forces a memory allocation failure on the indicated attempt. Use it to test how well your client or provider handles memory allocation failures. The count includes blocks allocated by MAPI and by other components, not just by your own component.
FailureInterval = number of allocations
This entry forces repeated memory allocation failures at the specified interval after the count indicated by the AllocsToFirstFailure entry is reached. The count includes blocks allocated by MAPI and by other components, not just by your own component.
FailureSize = number of bytes
If this entry is nonzero, this entry forces every memory allocation request for the specified number of bytes or more to fail. This includes blocks allocated by MAPI and by other components, not just by your own component.