Reverse DNS does not match SMTP Banner

Hi, MXToolBox reports that our reverse DNS does not match the SMTP Banner even though it should. I've made the following changes: Exim configuration: Send mail from account"s dedicated IP address: Off Reference /etc/mailhelo for outgoing SMTP HELO: On Reference /etc/mailips for outgoing SMTP connections: On

smtp_banner = "${smtp_active_hostname} ESMTP Exim ${version_number}  \#${compile_number} ${tod_full} \n   We do not authorize the use of this system to transport unsolicited, \n   and/or bulk e-mail."

smtp_active_hostname =
${lookup{$interface_address}lsearch{/etc/mail_reverse_dns}{$value}{$primary_hostname}}

message_id_header_domain = $smtp_active_hostname

/etc/mailips:
*: 10.0.0.251
/etc/mail_reverse_dns:
10.0.0.251: pro5mail.example.com
/etc/mailhelo:
* : pro5mail.example.com
When trying to telnet, it reports the correct hostname:


[root@server10 ~]# telnet pro5mail.example.com 25
Trying *.*.*.251...
Connected to pro5mail.example.com.
Escape character is '^]'.

What could the issue be?

cPanelMichael

December 04, 2017 18:00

Hello, Sometimes it's a false positive from the MXToolBox website due to the "Introduce a delay into the SMTP transaction for unknown hosts and messages detected as spam." option under the "ACL Options" tab in "WHM >> Exim Configuration Manager >> Basic Editor". See: SOLVED - Reverse DNS does not match SMTP Banner (Problem) Thank you.

DennisMidjord

December 05, 2017 07:34

Disabling that option temporarily also shows only green checkmarks on MXToolBox. Thanks, Michael!

WorkinOnIt

December 02, 2020 20:45

Following this for future reference as this was a great tip - once disabled it fixed my issue.

Xzone9

April 19, 2021 13:19

This issue and resolution is still valid. Works for me.

sitespt

June 02, 2021 17:35

Worked for us too. Thanks.

Reverse DNS does not match SMTP Banner

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