All received email bounces back, can still send emails

Operating System & Version
cPanel & WHM Version
106.0 (build 14)

Michael Sam

Jan 29, 2023
cPanel Access Level
Root Administrator
Recently started getting multiple errors without changing any settings anywhere

550 "JunkMail rejected - []:53886 is in an RBL: open resolver; DNSBL Error Code - Open/public resolver - The Spamhaus Project"

another error that popped up today is:

Delivery incomplete
There was a temporary problem delivering your message to [email protected]. Gmail will retry for 50 more hours. You'll be notified if the delivery fails permanently.
The response was:
DNS Error: DNS type 'mx' lookup of responded with code NOERROR DNS type 'aaaa' lookup of responded with code NXDOMAIN DNS type 'a' lookup of responded with code NXDOMAIN

I've checked the DNS records on my provider ( and they're attached as below
any insights as to why any of this is happening and how to resolve it?


Last edited by a moderator:


Jurassic Moderator
Staff member
Oct 19, 2014
cPanel Access Level
Root Administrator
Hey there! I don't have an explanation for the second issue, as your DNS and MX records look fine to me, and the mailserver is responding how I would expect.

For the first issue, your likely are using Google, or other public resolvers in your /etc/resolv.conf file, breaking the Spamhaus lookups. You'll want to contact your datacenter and ask what IP addresses should be configured in that file, and that will take care of the issue once it is adjusted.