Hi, first time cloudron user here.
Cloudron version: 9.0.10
Ubuntu version: Ubuntu 24.04.3 LTS Linux 6.8.0-87-generic
Vendor: Hetzner VPS
Sometimes I am getting an error that my IP4 is blacklisted on spamhaus. But checking with spamhaus does not confirm my IP is blacklisted. It seems to be the "open resolver" issue.
Some emails sent to me are not delivered but returned with this error message:
Client host [**.**.***.***] blocked using
zen.spamhaus.org; Error: open resolver;
I read somewhere that this could be related to the Hetzner public DNS. But I do not know how to resolve this.
Spamhaus mentions steps to solve the issue by signing up to their Spamhaus DQS and making relevant changes to the mail server configuration.
It is not clear to me which steps I have to take in regards to the Cloudron setup.
Can someone help me solve this issue? I am not very technical but do have SSH access to my server.
