+mimetype-file::
+ Specifies the file to use for automatic mimetype lookup. If specified
+ then this field is used as a fallback when no "mimetype.<ext>" match is
+ found. If unspecified then no such lookup is performed. The typical file
+ to use on a Linux system is /etc/mime.types. Default value: none. See
+ also: "mimetype.<ext>". The format of the file must comply to:
+ - a comment line is an empty line or a line starting with a hash (#),
+ optionally preceded by whitespace
+ - a non-comment line starts with the mimetype (like image/png), followed
+ by one or more file extensions (like jpg), all separated by whitespace
+