MyDefrag has a lot of Variables
you can use. For example:
FILES200P - The number of unfragmented files and directories on the volume in percent
FILES212P - The size of all the unfragmented files + folders on the volume in percent
Pick your favorite(s), then edit the Settings.MyD, search for "LogAfter" and add the variables enclosed in "!", just like the others. You can of course add the new variables to any other message.