unfortunately to go further I'd need to see the FULL message. ALL headers from top to bottom. First character of message to last. Your email address and some IP addresses will be in there, you can sub them if you want to but make sure to keep them clear as to their purpose. (change ip addresses to 256.256.256.256 for example, instead of deleting the line it's on)
I'd venture a guess that there's something somewhat nonstandard or unusual about the attachment format that's confusing mail.app
I thought I did copy everything and give it to you. Maybe not the header, just the body of the message. This is happening from several companies like Amazon, a little nursery in my town, the post office and other entities that come into my Yahoo mail. Would a screen shot be better?
