'Send a DELE command to delete a message from the server.
@type index: L{int}
@param index: The 0-based index of the message to delete.
@rtype: L{Deferred <defer.Deferred>} which successfully fires with
L{bytes} or fails with L{ServerErrorResponse}
@return: A deferred which fires when the server response is received.
On an OK response, the deferred succeeds with the server
response minus the status indicator.  On an ERR response, the
deferred fails with a server error response failure.'

def delete(self, index):

    return self.sendShort('DELE', str((index + 1)))
