Thank you for your hint Ralph - the domain could be spoofing :-), but yes you are right, its non exit traffic.
@nusenu: what whould be this list without you - thanks!!
Based on your email domain and your question about a dynamic DSL link, I'm guessing you are considering running a Tor relay at home? As stated in https://www.torproject.org/docs/faq-abuse.html.en : "In general, it's advisable not to use your home internet connection to provide a Tor relay."
-Ralph