[StAPF] Undelivered Mail Returned to Sender

This is the mail system at host mail.zapf.in. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to postmaster. If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <felix.farsch(a)fachschaft.physik.tu-darmstadt.de&gt;: host b2681.mx.srv.dfn.de[194.95.235.42] said: 550 5.1.1 <felix.farsch(a)fachschaft.physik.tu-darmstadt.de&gt;: Recipient address rejected: undeliverable address: host mailin-dfn.hrz.tu-darmstadt.de[130.83.156.225] said: 554-5.7.1 <felix.farsch(a)fachschaft.physik.tu-darmstadt.de&gt;: Recipient address rejected: E-Mailadresse unbekannt / email address unknown 554 5.7.1 Fuer weitere Hilfe wenden Sie sich bitte an Postmaster(a)hrz.tu-darmstadt.de Bitte fuegen Sie folgende Informationen hinzu: Zeitpunkt (Apr 23 15:49:57) und Server (mail-relay225.hrz.tu-darmstadt.de) (in reply to RCPT TO command) (in reply to RCPT TO command)