our entire office is running 1.0.3 and 1.0.4 versions of Zimbra Desktop Client on OS X 10.5 and 10.6 but out of the 50 machines, only 1 appears to have Drag n' Drop file attachment capability. After reading through the forums, we have verified this by making sure that they are attach files through an embedded compose window versus a pop up, but no luck.
In addition, I had thought that a configuration conflict may be the issue so ran a test by installing ZDC on a fresh install of OS X with no additional changes or other software installations and still cannot get drag n' drop to work.
Does anyone have any other suggestions how to get this to work? My office is very frustrated over this, and joining my organization in October this was the first time I found out that the feature is supposed to be there.