Hey Jan,
Sorry for the delay of this reply. I don't mean to be rude here but if you would have included your access in this post, you might get a reply much sooner. We deal with over 100 posts each day, I don't think we can really remember which post has access and which post doesn't. Let alone, you post your access in replies on another thread and not the main question. So we need to read through the entire post to find your access.
Anyways, this is the error when Komento's cron is executed,
JMail::Send failed: "Impossible de connecter par SMTP".
This error is being returned by Joomla and not Komento as Komento just utilizes the API from Joomla to send email. You need to check your Mandrill app logs.
Thank you for understanding and appreciate that you could include accesses in your reply or add your details once at
http://stackideas.com/dashboard/site