The original message was received at Tue, 24 Oct 2023 13:38:58 +0200 (CEST) from btr0xj [132.180.8.25] ----- The following addresses had permanent fatal errors ----- <max-peter.menzel@uni-bayreuth.de> (reason: 550 5.1.1 <max-peter.menzel@uni-bayreuth.de>... User unknown) ----- Transcript of session follows ----- ... while talking to [127.128.8.11]:

...

...

DATA <<< 550 5.1.1 <max-peter.menzel@uni-bayreuth.de>... User unknown 550 5.1.1 <max-peter.menzel@uni-bayreuth.de>... User unknown <<< 503 5.0.0 Need RCPT (recipient)