I noticed that they all have a very long line of spaces after the "X-Keyword:" header line.
I also noticed that "header NAME X-Keyword:\s\s\s\s" simply does not work. It gets tokenized down to one blank. But a FULL test seems to be able to catch it. full JD_SPACES_KEYWORDS /X-Keywords:\s\s\s\s\s\s\s\s\s\s\s\s/i describe JD_SPACES_KEYWORDS X-Keywords with lots of spaces score JD_SPACES_KEYWORDS 4.5 I am watching for false alarms. That is why I have it scored so high. It's a quick ad hoc test on my own email stream. (They contain a fair amount of HTML in the message which may be a fruitful test, too.) {^_^}