Sorry I'm not familiar with the whitelist and blacklist terms. I essentially took the idea from jsdom encode function found [here](https://github.com/tmpvar/jsdom/blob/master/lib/jsdom/browser/htmlencoding.js). However instead of the specialCharacters object they created, I figured perhaps a regex would be faster at parsing the html and encoding the entities found. Also, they use named entities instead of the numerical version which I've found to not be as reliable in some email clients. 

On a side note, my wife Becky Nieto says she knows you from Skyview and says Hi lol. Small world.