The MAPIAllocateBuffer function allocates a memory buffer.
During MAPIAllocateBuffer call processing, the calling implementation acquires a block of memory from the operating system. The memory buffer is allocated on an even-numbered byte address. On platforms where long integer access is more efficient, the operating system allocates the buffer on an address whose size in bytes is a multiple of four.
Calling the MAPIFreeBuffer function releases the memory buffer allocated by MAPIAllocateBuffer and also releases any additional buffers that have been linked to it through the MAPIAllocateMore function.