code: function (rawEmail, callback) {
          if (!isSpamcAvailable) {
              return callback(null, 0.0);
          }
  
          spamc.report(rawEmail, function (err, result) {
              logger.verbose(result);
              if (err) logger.error(err);
              if (err) return callback(new Error('Unable to compute spam score.'));
              callback(null, result.spamScore);
          });
      }
docs: /* @param rawEmail is the full raw mime email as a string.