How to remove an ip of my mail server from the blacklist sophos?

Hi, I have a problem your mail server is rejecting the emails from my mail server.
Mistake:
: host mx-01-eu-central-1.prod.hydra.sophos.com[3.127.4.120] said: 554 5.7.1
Service unavailable; Client host [89.34.236.192] is blacklisted.

Thank you