<sebastian.ertl@web.de>:
217.72.192.149 does not like recipient.
Remote host said: 550 <sebastian.ertl@web.de> Benutzer hat zuviele Mails auf dem Server. / User has too many messages on the server.
Giving up on 217.72.192.149.

<cac.geiger@student.uni-augsburg.de>:
137.250.121.11 does not like recipient.
Remote host said: 550 Unknown local part cac.geiger in <cac.geiger@student.uni-augsburg.de>
Giving up on 137.250.121.11.

<johanna.pix@stud.uni-regensburg.de>:
132.199.1.15 does not like recipient.
Remote host said: 550 <johanna.pix@stud.uni-regensburg.de>: Recipient address rejected: User unknown in virtual alias table
Giving up on 132.199.1.15.