Can I Disable The Attachment Preview In OS X Mail?
To disable attachment preview in OS X, launch the Terminal from your Applications folder and enter the following command:
defaults write com.apple.mail DisableInlineAttachmentViewing -bool yes
Relaunch Mail for your changes to take effect.
If you ever want to bring back attachment preview you can enter the following in Terminal:
defaults write com.apple.mail DisableInlineAttachmentViewing -bool no