BCCs are not kept secret

[jasen-b]

BCCs are not kept secret:

This code in private function createHeaders($filedata) is to blame:

    if (!empty($this->bcc)) {
        $this->ahead[] = 'Bcc: '.$this->formatAddressList($this->bcc);
    }

[s22-tech]

Check out my fork at PHP-SMTP-Mailer. It fixes a few other things, as well, and requires PHP 8+.