Ssimple MAPI send with attachments inserts spaces

I recently ran into a bizarre behavior with Outlook 2003 and 2007 (haven't
tested any others) and the Simple MAPI MAPISendMail function with attachments.

I'm creating a MapiMessage with only attachments in it. As long as there is
more than one attachment, for some reason the send mail dialog that pops up
has 2 spaces in the body for each attachment.

Here's the relevant code. count is the number of attachments:

MapiMessage *const pMsg = new MapiMessage;
ZeroMemory(pMsg, sizeof(MapiMessage));
pMsg->lpFiles = new MapiFileDesc[count];
ZeroMemory(pMsg->lpFiles, sizeof(MapiFileDesc) * count);

for (int i = 0; i < count; i++) {
CString filePath(...); // This is where the path to the attachment is
set - details are not relevant to this snippet
pMsg->lpFiles[pMsg->nFileCount].nPosition = -1;
pMsg->lpFiles[pMsg->nFileCount].lpszPathName = new
char[filePath.GetLength() + 1];
strcpy(pMsg->lpFiles[pMsg->nFileCount].lpszPathName, filePath);
pMsg->nFileCount++;
}

if (AfxBeginThread(sendEmailThread, pMsg) == NULL) {
deleteMsg(pMsg);
}

All the sendEmailThread does is call:
MAPISendMail(NULL, NULL, pMsg, MAPI_LOGON_UI | MAPI_DIALOG);

So the only somewhat odd thing going on here are that the MapiMessage is
created in one thread and sent on another. But I tried doing it all in the
same thread and it behaves the same.

As a test I tried setting the body to something other than NULL (I tried
both "" and "test") and in both cases I get the extra spaces plus a new line
before the specified text.

So, either this is a bug in Outlook (neither Outlook Express nor Windows
Mail do it) or I'm missing something. I looked through the flags for the
message itself and the MAPISendMail function and I didn't see anything that
seemed relevant.

The same behavior also occurs when doing a send to mail recipient in Windows
Explorer, which strongly suggests a bug in Outlook.

Any ideas?

Thanks,
Mark Smith