This is a new feature to 6.1x (but it isn't quite exactly what you want, but it does a damn good job).
Go to Tools > Options > DCC and in the on SEND section, you'll see a button labelled "Trusted"
Click on this, and you are now able to manipulate a list of trusted clients for DCC gets. One of the options there is to limit the auto get to those only in the trusted list.
Nice and handy feature
