Deltacopy Version 1.4 will not copy directory and file names containing Umlauts
or special characters via rsync to a NAS running OMV 3.x.
The solution as supplied by the makers of Deltacopy:
"Please try updating the cygwin DLLs that come with DeltaCopy to the latest version.
You may have to install CYGWIN and then manually copy the DLLs to the installation folder of DeltaCopy."
This worked perfectly.