[StAPF] Delivery Status Notification (Failure)

The following message to <christoph.jansen(a)hs-flensburg.de&gt; was undeliverable. The reason for the problem: 5.1.0 - Unknown address error 550-'[SPF] 129.206.119.212 is not allowed to send mail from zapf.in. Please see\nhttp://www.openspf.org/Why?scope=mfrom;identity=stapf@zapf.in;ip=129...