I see on the AppStore there is only one version of the SMTP Email Module. I haven't used this before - but it might be this module is not compatible with Mendix 7 (yet). I would file a support ticket with Mendix for this. I myself always use the E-mail module with templates.
The Mendix Runner seems to be obsolete. As a short circuit solution you can replace it with a standard Java runnable (untested snippet)
{
final Message message = new Message();
message.setPlainBody(plainmsg);
message.setHtmlBody(htmlmsg);
final Sender sender = new Sender(context);
Runnable runnable = new Runnable()
{
@Override
public void run() {
sender.send(configuration, message, subject, to, cc, bcc, attachments, headers);
}
};
Thread thread = new Thread(runnable);
thread.start();
}