An expression evaluating to an object
of type XMPPFile.
value
A String value. Holds MIME type of the file.
Remarks
This property will return MIME type of the file. It defaults to
'binary/octet-stream' but you can
change it to more appropriate value when you know type of the file
you send (such as 'image/png' or
similar). This value is sent to remote side when file transfer is
requested. You can also fine here MIME type of the file offered by
remote side, if you are downloading the file.