DKIM pubkey_syntax error for incoming mail

NOC SZ

Member
Sep 13, 2017
7
0
1
Dubai
cPanel Access Level
Root Administrator
Hello,

For the last few days one of my client having this issue of not being able to send email to me. They are getting a bounce back saying "
550-'DKIM: encountered the following problem validating clientdomain.com:
pubkey_syntax'"

Is this because of some issues with my server or their?
Below shows the bounce back message they are getting:

=============

[email protected]
[MYIP] #<[MYIP] #5.0.0 smtp; 5.3.0 - Other mail system problem 550-'DKIM: encountered the following problem validating clientdomain.com:
pubkey_syntax' (delivery attempts: 0)> #SMTP#

Original message headers:

Received-SPF: None (mail.clientdomain.com: no sender authenticity

information available from domain of [email protected])

identity=pra; client-ip=10.1.60.33; receiver=mail.clientdomain.com;

envelope-from="[email protected]";

x-sender="[email protected]";

x-conformance=sidf_compatible

Received-SPF: SoftFail (mail.clientdomain.com: domain of

[email protected] is inclined to not designate 10.1.60.33

as permitted sender) identity=mailfrom; client-ip=10.1.60.33;

receiver=mail.clientdomain.com; envelope-from="[email protected]";

x-sender="[email protected]";

x-conformance=sidf_compatible; x-record-type="v=spf1"

Received-SPF: None (mail.clientdomain.com: no sender authenticity

information available from domain of
=====================

my OS: CentOS release 5.11 (Final)
cpanel version: WHM 54.0 (build 8)

I tried disabling "reject dkim failures" in WHM, but it for some reason blocking mails from gmail to me. Strange! Now I completely disabled DKIM in WHM by turning "Allow DKIM verification for incoming messages" to off in WHM

This is the log I found in exim_mainlog
1dqyMW-0004zt-Ix DKIM: d=clientdomain.com s=DKIMSelector c=simple/simple a=rsa-sha256 [invalid - syntax error in public key record]
1dqyMW-0004zt-Ix H=mail.clientdomain.com (mail.clientdomain.com) [clientIP]:26646 I=[myIP]:25 X=TLSv1:DHE-RSA-AES256-SHA:256 CV=no rejected DKIM : DKIM: encountered the following problem validating clientdomain.com: pubkey_syntax


Any help would be appreciated.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,913
2,205
363
Hello,

Now I completely disabled DKIM in WHM by turning "Allow DKIM verification for incoming messages" to off in WHM
Can you verify if the issue persists, even after disabling that option? Also, the version of cPanel you are using is end-of-life and no longer supported:

cPanel & WHM Version 54 Now EOL, Cent 5 & Cent 6-32bit in 3 Months | cPanel Newsroom

Is there anything we can do to assist you in transferring your accounts to a server using CentOS 6 or 7, with a more recent version of cPanel?

Thank you.
 

NOC SZ

Member
Sep 13, 2017
7
0
1
Dubai
cPanel Access Level
Root Administrator
Hi Michael,

Thanks for the prompt reply, appreciate it. We are having this issue with only one domain, from which we haven't received any other mail. They will be sending again, will update you then.

I know the cPanel version is EOL, we will move soon. For the time being I need to stick with this and sort this out.
Is there any particular reason for this error?

Thank you!
 

NOC SZ

Member
Sep 13, 2017
7
0
1
Dubai
cPanel Access Level
Root Administrator
UPDATE!!

We are able to receive the mail now. But still have some doubts.

I tried disabling "reject dkim failures" in WHM, but it for some reason blocking mails from gmail to me
this was the bonce back message I received :
============

Message not delivered
There was a problem delivering your message to [email protected]. See the technical details below, or try resending in a few minutes.
The response was:

550 Administrative prohibition
============

Any idea why this is happening?
 
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