looks like one email accidentally passed through the auto-reply and was sent to the old list. I can't find any setting to disable a list and/or force a reply saying about the new list location:
Right now I've put everyone on moderation and will reply directly to the sender if one email slips. I'm forwarding the old email to the new list too.
Please update your address books to the new aerogear-dev(a)lists.jboss.org address, and let's hope no email goes unnoticed to the old list.