[otrs]Change destination email address of notifications

Hello, today, the administrator of our Email-Server reported that Znuny had sent an email to root@postamt.cs.uni-dortmund.de, postamt being our Email-Server. Obviously, that destination address does not make such sense. Unfortunately, I could not find so far how to change destination email addresses. Where can that be done (latest Znuny version)? Regards Christoph