Swift_Signers_DKIMSigner::addHeader PHP Method

    protected function addHeader($header, $is_sig = false)
    {
        switch ($this->headerCanon) {
            case 'relaxed':
                // Prepare Header and cascade
                $exploded = explode(':', $header, 2);
                $name = strtolower(trim($exploded[0]));
                $value = str_replace("\r\n", '', $exploded[1]);
                $value = preg_replace("/[ \t][ \t]+/", ' ', $value);
                $header = $name . ':' . trim($value) . ($is_sig ? '' : "\r\n");
            case 'simple':
                // Nothing to do
        }
        $this->addToHeaderHash($header);
    }