Mail keeps redirecting Emails

Hi support community,

I have a very urgent problem: Yesterday I tried out "redirect", which seemed to work flawlessly. However, I did not know that this would be permanent in Mail. Another email had been redirected as well... which was not to my benefit at all.

Anyways, I can not see any rules, that say that all emails from person a are automatically redirected to person b. How do I get this redirection off??

Thank you in advance for your answers

DerMagga