title: Jruby check if JavaMail headers contains a specific name
body: <p>On a JavaMail POP3Message there's a method to get all header lines which returns an Enumeration of name and value. I know I can traverse this and check if a specific header name exists but am thinking there may be a better way to do that but can't find it. Is there any faster/better alternative solution than having to traverse everything from Jruby? </p>