Content-Type: text/plain
Content-Disposition: inline
Content-Transfer-Encoding: binary
MIME-Version: 1.0
X-Mailer: MIME-tools 5.411 (Entity 5.404)
RT-Send-CC:
X-RT-Original-Encoding: iso-8859-1
Content-Length: 317

On all platforms the format for a keytab or a ccache is <TYPE>:<name>.

The proper format would be 

   FILE:d:\path\file

However, there is some magic glue that is supposed to work to
auto-detect a drive letter and guess from that it is a FILE: type.  The
fix for this was pulled up to the release branch tonight.