Reverse DNS does not match SMTP Banner

[oomaro]

" Reverse DNS does not match SMTP Banner "
10 Dayes, I spend it reading and tried all resolved posts here, but no one solve the problem.
what is that?
Who can help or we will leave cPanel forever and going to anther services?
Reverse DNS does not match SMTP Banner
how can we fix it please do not share any linked I read all even those from 2016.

 

[cPRex]

Hey there! I'm sorry to hear about the issues with the reverse DNS configuration. The reverse DNS should point to the hostname of the server. However, there isn't a way to fix it on the server itself - you *have* to contact your hosting provider or datacenter to have them set that up. Once they do that, it should start working immediately for you.

 

[oomaro]

I can receive Emails. I can't send emails. and after I tried all the methods here I got only this " Reverse DNS does not match SMTP Banner "
you know I rebuilt the VPS. the problem still exists. I contacted the DC provider he said contact cpanel admin.

 

[quietFinn]

Your DC provider is an idiot

 

[cPRex]

@oomaro - you would first want to confirm the reverse DNS is in place. You can do that with the "dig -x" command, or with an online tool like Reverse IP Lookup - MxToolbox. If that works properly, can you check and see if there are any customizations to the /etc/mailhelo file on the system? By default, this file should contain one line, that looks similar to the following:

*: host.domain.com

 

[oomaro]

whatever you think I tried it. but the problem still I can receive emails. I can't Send. it hung in queue mail.

 

[oomaro]

@oomaro - you would first want to confirm the reverse DNS is in place. You can do that with the "dig -x" command, or with an online tool like Reverse IP Lookup - MxToolbox. If that works properly, can you check and see if there are any customizations to the /etc/mailhelo file on the system? By default, this file should contain one line, that looks similar to the following:

*: host.domain.com

yes for /etc/mailhelo only the reverse static IP. only one line and it is the same DNS reverse that is in the VPS Ip static.

 

[cPRex]

These specific errors aren't related to the reverse DNS. Have you worked through all the options listed here? https://support.cpanel.net/hc/en-us/articles/360047748814-Could-Not-Complete-Sender-Verify

 

[oomaro]

I did it but that

/scripts/mailperm $user


given me nothing.

 

[cPRex]

That's normal - there may not be output from that command.

For the mails that are sitting in the queue, what does the Exim log show? The full mail transaction would be in /var/log/exim_mainlog.

 

[cPRex]

I removed that last post because it was just too much information. We just need to see one specific failed email transaction in the log showing what is currently happening on the system.

 

[quietFinn]

You can do:
exigrep "Message ID" /var/log/exim_mainlog

Message ID you can see in Mail Queue Manager.

 

[oomaro]

I removed that last post because it was just too much information. We just need to see one specific failed email transaction in the log showing what is currently happening on the system.

how can I attach it here text not allowed

 

[oomaro]

I also open ticket with cPanel. they said open port 25 does not open I don't have external firewall.
cPanel said check with you DC VPS provider.
DC VPS admin said Problem with cPanel and EXIM. specially happened. If I have domains. but if I have only one domain it will work fine.
I hate to be like a Pingping ball.

 

[cPRex]

Can you please let me know the ticket number you have opened with us?

 

[oomaro]

95126929

 

[cPRex]

Thanks for that. That confirms that outbound connections over port 25 are being blocked by your hosting provider. This is very common, and we have details on this here:

https://support.cpanel.net/hc/en-us/articles/360053203653-How-To-Send-Email-When-Your-Server-Provider-Blocks-Port-25

Your only options are to work with your host, or setup a smarthost to send email.

 

[oomaro]

the port is up !!

 

[cPRex]

That test makes an inbound connection. Can you run this command from your server?

telnet gmail-smtp-in.l.google.com 25

 

[quietFinn]

Usually telnet is not installed by default, in that case you can install it:
yum -y install telnet