What happens when you try to open an attachment? What type of attachment we're talking about? With which application do you want to open the attachment?

The attachment was a scanned image. When I click on the attachment icon nothing happens. I do not get a chance to choose a program to open it. the icon remains inactive.

What happens if you right click an attachment? Is there an option to save it?

Does the attachment have a name that accurately represents what it is? If "scanned image" means it is something produced by a desktop scanner, then it would be a graphic and should be a PDF, PNG or similar.