The Zimbra Drag and Drop Firefox extension allows users of Zimbra Collaboration Suite 5.0+ to drag files directly from their PC to the Compose and Briefcase window. It now supports Windows, Mac and also Linux.
com_zimbra_dnd.zip must be installed on the ZCS server. This can be found in /opt/zimbra/zimlets-extra. Use zmzimletctl deploy com_zimbra_dnd.zip to deploy the zimlet.
Drag and Drop the file into the compose or briefcase window.