How to fix misuse of spamhaus blocklist?

Question

Email

Greetings comrades!
A couple of days ago I stopped receiving mail from some domains. I see messages in the logs

reject: RCPT from venus.servername [xxx.xxx.xxx.xxx]: 554 5.7.1 Service unavailable; Client host [venus.servername] blocked using sbl.spamhaus.org; SPAMHAUS BLOCKLIST WRONGLY USED AS A RHSBL LIST! MUST FIX; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<venus.servername>

To be honest, this is the first time I see this, and I don’t even know how to edit
Zimbra 8.6.0

Answer 1

You are using sbl.spamhaus.org as an RHSBL (i.e. a domain name blacklist, in this case for a PTR host), while it is an IP address blacklist, configure the correct blacklist type, make sure in sbl.spamhaus.org the IP address is transmitted.