Issue with SMTP Server (Exim) Receiving Mail, 550 Administrative Prohibition

apsarah

Registered
Sep 19, 2015
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I'm currently experiencing issues with inbound mail not getting passed the EHLO / HELO step during an inbound SMTP transaction.

I have tried toggling the "Require HELO before MAIL" option on and off (Service Configuration>Exim Configuration Manager>All), as well as restarting the service, rebooting the server, and rebuilding exim, but unfortunately none of these worked.

Please see the below SMTP output (Port 25 of below hostname)

Code:
220-eha.domain.com ESMTP Exim 4.85 #2 Sat, 19 Sep 2015 03:06:56 -0500
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
HELO google.com
550 Administrative prohibition
quit
221 eha.domain.com closing connection
Has anyone experienced this before? What did you do to fix this?
 
Last edited by a moderator:

cPanelMichael

Administrator
Staff member
Apr 11, 2011
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Hello :)

Do you have any custom options enabled in the /etc/exim.conf.local file on this system? Does this happen when using HELO names other than google.com?

Thank you.
 

Jcats

Well-Known Member
PartnerNOC
May 25, 2011
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DataCenter Provider
Can you see if anything helpful shows if you
Code:
# tail -f /var/log/maillog /var/log/exim_mainlog
while sending a test email
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
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New Hi, I haven't enabled any custom options for exim, and yes it happens for other HELO values.
Hello :)

You can search for one of the email addresses that's failing to proceed past the HELO check in the Exim logs with commands such as:

Code:
exigrep [email protected] /var/log/exim_mainlog
exigrep [email protected] /var/log/exim_rejectlog
Do you notice any particular output that helps clarify the reason for the rejection?

Thank you.
 

apsarah

Registered
Sep 19, 2015
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Perth
cPanel Access Level
Root Administrator
Thanks for everyone's help, I reviewed the exim settings and found a HELO reject subroutine which was anticipated to prevent connections at HELO from a specific host. It appeared to be causing the issue, as after removing the aforementioned subroutine, the SMTP system returned to normal.

Thanks again everyone.
 

cPanelMichael

Administrator
Staff member
Apr 11, 2011
47,884
2,250
463
I am happy to see the issue is now resolved. Thank you for updating us with the outcome.