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SOLVED Reverse DNS does not match SMTP Banner

Discussion in 'E-mail Discussion' started by DennisMidjord, Dec 1, 2017.

  1. DennisMidjord

    DennisMidjord Well-Known Member

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    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

    Code:
    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:
    Code:
    *: 10.0.0.251
    /etc/mail_reverse_dns:
    Code:
    10.0.0.251: pro5mail.example.com
    /etc/mailhelo:
    Code:
    * : pro5mail.example.com
    When trying to telnet, it reports the correct hostname:
    Code:
    [root@server10 ~]# telnet pro5mail.example.com 25
    Trying *.*.*.251...
    Connected to pro5mail.example.com.
    Escape character is '^]'.
    What could the issue be?
     
  2. cPanelMichael

    cPanelMichael Forums Analyst
    Staff Member

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    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.
     
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  3. DennisMidjord

    DennisMidjord Well-Known Member

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