I'm still migrating from Wordpressing to Bootstrapping.<br />
Great question - haven't thought of it much because I use PHP for mail functions but a quick search turned up this article The are of web which may be a start. As I have time to look more I'll see if I can find better guidance. Additionally since the sneaky google bots are constantly find ways to mine data from websites maybe an additional HTML directive to stop Google searches will help also. I need to lookup the directives and can provide them when I have them. I haven't tested any of this - just providing to maybe further your research.