Remote server can't resolve email sender domain

[Malagana]

Hi, a couple days ago I updated my server to WHM v74.0.9 but right now some accounts with dedicated IP address are having issues sending and receiving email from and to certains domains. The weird thing is that If we sent email from one host account ussing the main server ip address to those domains the emails are delivered OK

The exim message is the following:

SMTP error from remote mail server after pipelined MAIL FROM:<[email protected]> SIZE=124910: 451 4.1.8 Domain of sender address [EMAIL][email protected][/EMAIL] does not resolve

And also for the domain where we are sending our email

retry time not reached for any host for 'to-client-domain.com'

The sender from one of the domains with this issue get this message:
451 xxxx.com Name server timeout

• Our domain is resolving OK
• We have checked PTR records and are OK
• We dont have any firewall issues

Any Ideas?

 

[24x7server]

Hi,

There is a setting in the WHM like the one mentioned below. Can you check if that is enable?

Enable the Send mail from account's dedicated IP address option in WHM's Exim Configuration Manager interface [ Home >> Service Configuration >> Exim Configuration Manager ].
How to Configure the Exim Outgoing IP Address - cPanel Knowledge Base - cPanel Documentation

 

[Malagana]

Hi,

The setting “Send mail from the account’s IP address” is enabled, each acccount that has a dedicated IP address has is PTR record OK so the sending domains resolve to the dedicated IP.

I don’t know if this is a DNS issue or where to look to know what is happening here. Since the remote server can’t find or resolve the email senders domain on our server

I didn’t do anything else besides the update to WHM.

 

[cPanelLauren]

Hi @Malagana

Do you have anything in /etc/mailhelo?

 

[Malagana]

@cPanelLauren yes we have some content in the /etc/mailhelo and /etc/mailips file but the next two options are off right now


Reference /etc/mailhelo for outgoing SMTP HELO
Reference /etc/mailips for outgoing SMTP connections

 

[cPanelLauren]

HI @Malagana

Is it only occurring with specific IP addresses or all of the dedicated IP addresses?

 

[Malagana]

HI @Malagana

Is it only occurring with specific IP addresses or all of the dedicated IP addresses?

Hi, Lauren this behavior happens with domains using a dedicated IP address, but not with all e-mail recipients.

 

[cPanelLauren]

Hi @Malagana


Does the issue persist if you remove the data from

/etc/mailhelo

(regardless of whether or not you have the setting to reference it enabled)

Also, can you run a successful traceroute to the IP addresses in question?

 

[Malagana]

Hi @Malagana


Does the issue persist if you remove the data from

/etc/mailhelo

(regardless of whether or not you have the setting to reference it enabled)

Also, can you run a successful traceroute to the IP addresses in question?

Hi, Lauren


Right now the domain is using the info on /etc/mailhelo and /etc/mailips using the server IP instead the dedicated for sending emails, with the sames results. Below are the response from the remote mail server when I tested from Telnet:

telnet INBOUND.pok.com.mx.NETSOLMAIL.NET 25

HEK220 inbound.net.registeredsite.com ESMTP SMTP Service (NO SPAM/UCE)                                                                               
helo c2e-us.net
250 atl4mhib41.myregisteredsite.com Hello chrome.cliccreativelabs.com [142.44.136.138] (may be forged), pleased to meet you
mail from: [email protected]
451 4.1.8 Domain of sender address [email protected] does not resolve
Connection closed by foreign host.

Regarding to the accounts with dedicated IP we can send mails without problems to others domain, the webs are resolving OK and also I can traceroute to the dedicated IP without problems from other machines.

I'm going to try deleting the content inside /etc/mailhelo but until now nothing seems to work.

I do'nt know if is something that we can't fix from our side.

 

[cPanelLauren]

I'm going to try deleting the content inside /etc/mailhelo but until now nothing seems to work.

Let me know how it goes removing the information there - if this doesn't work can you please open a ticket using the link in my signature? Once open please reply with the Ticket ID here so that we can update this thread with the resolution once the ticket is resolved.


Thanks!

 

[Malagana]

Let me know how it goes removing the information there - if this doesn't work can you please open a ticket using the link in my signature? Once open please reply with the Ticket ID here so that we can update this thread with the resolution once the ticket is resolved.


Thanks!

Hi, Lauren

The support request ID is
10623945

 

[cPanelLauren]

Hi @Malagana


Thanks for that, I've found the ticket and I'm currently watching it. I'll update here with the outcome when available.


Thanks!