Upload a document via email - broken

Hi,
I've been experimenting with forwarding emails with attachments to the project email alias (<portal>_<projectstring> @document.zohoprojects.com) and they keep getting returned, saing there were no valid attachments found in the mail.

I'm sending from Mail on the Mac (OS Lion) and the attachment was a 15k JPEG image.

This seems like it should be a no-brainer, but it is not working... Any tips?

thanks,
clark