Just got notification that my IP is blacklisted fro misconfiguration

Operating System & Version
CENTOS 7.8
cPanel & WHM Version
v88.0.13

Jeromero

Active Member
Aug 6, 2019
25
3
3
Johannesburg , South Africa
cPanel Access Level
Website Owner
Hello all,
I just got notification that my IP is blacklisted fro misconfiguration.
When I do the query at Query and delist – SPFBL.net it says
"This IP was flagged due to misconfiguration of the e-mail service or the suspicion that there is no MTA at it."
Does anyone know what should I do?
 
Last edited by a moderator:

ZenHostingTravis

Well-Known Member
PartnerNOC
May 22, 2020
163
52
28
Australia
cPanel Access Level
Root Administrator
Hi,

Firstly, if you go to mxtoolbox.com and search for your server's IP, are you on any other blacklists and are you having issues with emails not being delivered or are you just concerned about this warning?
 

Jeromero

Active Member
Aug 6, 2019
25
3
3
Johannesburg , South Africa
cPanel Access Level
Website Owner
Thanks, no on mxtoolbox.com they are all green. There is no problem with emails.
But yes, I am concerned about that warning and I have noticed that there is a delay in delivery of the emails when I send it to certain hosts especially to Microsoft Exchange (Office 365 users) where when I send the email it can take up to 12 hrs to be delivered or even just does not arrive to thir email acc.
 

ZenHostingTravis

Well-Known Member
PartnerNOC
May 22, 2020
163
52
28
Australia
cPanel Access Level
Root Administrator
Hi @Jeromero,

That's good that they are all green.

I'm not sure whether the issue with being on the blacklist and the slow delivery of email is related or not.

You could use the following tool: Email Header Analyzer, RFC822 Parser - MxToolbox

And then you could open a case with Microsoft.
 

cPanelLauren

Product Owner
Staff member
Nov 14, 2017
13,297
1,251
313
Houston
Thanks, no on mxtoolbox.com they are all green. There is no problem with emails.
But yes, I am concerned about that warning and I have noticed that there is a delay in delivery of the emails when I send it to certain hosts especially to Microsoft Exchange (Office 365 users) where when I send the email it can take up to 12 hrs to be delivered or even just does not arrive to thir email acc.
Which MXToolbox check did you do? Primarily you need to ensure that you have the following enabled and configured properly:

SPF for each domain sending mail
DKIM for each domain sending mail
PTR for the hostname of the server
DMARC for each domain sending mail - this is more or less optional at this point but not a bad move to make
 
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Jeromero

Active Member
Aug 6, 2019
25
3
3
Johannesburg , South Africa
cPanel Access Level
Website Owner
Ok after a few days figuring out what is happening I am coming to conclusion that the FCRDNS can be setup only on the main IP for my server.
Since I have a couple of more IP's and one of them is blacklisted on Query and delist – SPFBL.net for misconfiguration - obviously for the reason as the FCRDNS can not be setup on it.
Is there a workaround so all IP's on the server will have a valid FCRDNS?
 

cPanelLauren

Product Owner
Staff member
Nov 14, 2017
13,297
1,251
313
Houston
Is there a workaround so all IP's on the server will have a valid FCRDNS?
The workaround would be to actually add a PTR record for all IP's that would send mail.
 
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