In Apple Mail it is kind of confusing to have attachments displayed as full-view by default. Unfortunately, the setting to always show attachments as symbols is missing. But the following command, copied into terminal, will help (First close Apple Mail before you issue the command
defaults write com.apple.mail DisableInlineAttachmentViewing -boolean YES
To revoke this setting, just issue this command:
defaults write com.apple.mail DisableInlineAttachmentViewing -boolean NO
I have successfully tested this setting on Apple Mail Version 6.3 (1503) running on OS X 10.8.3. But it might aswell run in different versions!
Source / more info: