It looks like you've added a parameter called strDraft:
But you're not passing that parameter:
You need to add that parameter to your call (or make it optional, as the strAttachments parameter is).
Furthermore, I see that you've removed this code:
It's needed (when you start a new Outlook instance in code) to ensure that the VBA environment has been initialized properly. If you remove that code, you risk the function not being accessible via COM.
Also, check your Outlook code compiles OK (otherwise it wont expose the function). Also check your outlook security level is set correctly (low / medium).
Hope this helps