Disable preview of pdf in Mail under OS X Mavericks Known problem: Mail previews e.g. pdf attachments. I want to see it as symbol. I could right click and choose 'Show as symbol' but I want this as default. The old solution was typing into terminal:

defaults write com.apple.mail DisableInlineAttachmentViewing -bool yes


which seems not to work under Mavericks any more. Does anybody have a working solution for this?
I found this here to disable PDF preview in Apple Mail, and tested in on my Mavericks.

defaults write com.apple.mail DisableInlineAttachmentViewing -boolean true


So your were close.