Just started happening . . . I clearly drag the attachment, a .docx or .xlsx file over to the dock to drop on the application and open and instead it opens an eml file of the email, not the attachment. Grrrr . . .
MacBook Pro, OS X Mountain Lion (10.8.1)
Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work.
Isolating an issue by using another user account
If the problem is still there, try booting into the Safe Mode. Shut down the computer and then power it back up. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the grey Apple icon and a progress bar appear. The boot up is significantly slower than normal.
General information.
Why do attachments in Mail open as eml files when dragged to their application on the dock?
