Exim4 rejects emails due to DNSBL check (Spamhaus & Spamcop) – false positives?

[sHAsHiLx]

Hey everyone, I recently encountered an issue with Exim4 on HestiaCP where emails were getting rejected due to DNSBL checks in dnsbl.conf.

The error message was:

Rejected because 159.183.98.243 is in a black list at zen.spamhaus.org

However, after checking directly with Spamhaus, the IP is not listed. (https://check.spamhaus.org/results/?query=159.183.98.243)

Upon further investigation, I noticed that dnsbl.conf in Exim4 contains the following DNSBL entries:

bl.spamcop.net

zen.spamhaus.org

After temporarily removing these, email delivery started working as expected.

My questions:

• Is there a recommended way to manage or update DNSBL settings within HestiaCP?

• Could these particular lists sometimes cause false positives?

• Would it be better to have a configurable way to adjust these settings instead of hardcoded values?

I’d appreciate any advice or insights on best practices for handling this.

Thanks in advance!

[sahsanu]

Hi @sHAsHiLx

This topic has been discussed a lot of times

Take a look to several options to fix the issue:

Exim rejecting emails

Because Spamhaus rejects requests for some public dns resolvers. You can: 1.- Disable the spamhaus dnsbl (not recommended) 2.- Change the dns resolver used by your server to one not blocked by Spamhaus like 76.76.2.0 and 76.76.10.0 (Control D Free DNS) 3.- Use your own DNS recursive resolver like bind9, PowerDNS, unbound, etc. 4.- Create a free Spamhaus data query account and you could use your current dns resolvers.