Whats with the random words at the bottom of spam mail?

I was just looking at Microsoft Outlook from a while back when I was trying to get Yahoo to send mail to it, I got some of my Dads mail, some of which is spam. I was deleting it and paused for a second, and saw one that said "waggle roughen tartar desire don empress ruminate leeward may. notorious silicon croon monolith cretin rotor martha blossom or not beef substantial bissau songbag sense won mangle amnesia criteria honolulu derogatory pivate astronaut may." .... Makes no sense at all to me. Any ideas as to why this gibberish is there? I think I've seen it before so it's probably got something to do with getting past spamblockers or *something* but I dunno.