Fixing DMARC & Reverse DNS does not match SMTP Banner

mytpanel

• November 04, 2017 11:27

Hi everyone! So I've learned a ton about SPF and other sending authorizations, but using mxtoolbox, I still have the following issues. The site is - Removed -
1 Error(s) Category Host Result ] dmarc example.com DNS Record not found 7 Warning(s) Category Host Result dns example.com SOA Serial Number Format is Invalid dns example.com SOA Expire Value out of recommended range smtp gmr-smtp-in.l.google.com Reverse DNS does not match SMTP Banner smtp alt1.gmr-smtp-in.l.google.com Reverse DNS does not match SMTP Banner smtp alt2.gmr-smtp-in.l.google.com Reverse DNS does not match SMTP Banner smtp alt3.gmr-smtp-in.l.google.com Reverse DNS does not match SMTP Banner smtp alt4.gmr-smtp-in.l.google.com Reverse DNS does not match SMTP Banner
I've read on some threads that these "don't matter". That said, I'd like to still understand how to fix them. * I'm using Google DNS. * I'm using a third party mail relay, which is good for the SPF, everything works properly. * I have inbound emails forwarded directly through Google Domains to another email inbox. From what I understand: * The SOA warnings are built into the DNS server, and I likely do not have access to them unless I'm hosting my own DNS through cpanel. But what do I do to fix the dmarc & Reverse DNS?

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  cPanelMichael

  • November 06, 2017 16:51

  Hello, If the email and DNS is hosted on the cPanel server, you can setup the DMARC record using the "Add DMARC Record" instructions from the following document: Zone Editor - Documentation - cPanel Documentation The reverse DNS warnings appear to stem from Google. You won't be able to alter those records because they are controlled by Google as opposed to your cPanel server. Thank you.

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  amccristovao

  • July 18, 2020 23:50

  Hello, For the Reverse DNS does not match SMTP banner i got a solution it worked for me: at the top of exim.conf (line 2): disable_ipv6 local_interfaces = 127.0.0.1 : aaa.aaa.aaa.aaa : bbb.bbb.bbb.bbb : ccc.ccc.ccc.ccc smtp_active_hostname = ${lookup{$interface_address}lsearch{/etc/virtual/smtp_active_hostnames}{$value}} smtp_banner = "$smtp_active_hostname ESMTP $tod_full" exim.conf driver section (line 2015) remote_smtp: driver = smtp headers_rewrite = * ${perl{get_headers_rewrite}} f headers_add = "${perl{get_headers_rewritten_notice}}" interface = "${lookup{$sender_address_domain}lsearch{/etc/virtual/domainips}{$value}{aaa.aaa.aaa.aaa}{bbb.bbb.bbb.bbb}{ccc.ccc.ccc.ccc}}" helo_data = "${lookup{$sending_ip_address}lsearch{/etc/virtual/helo_data}{$value}{$primary_hostname}}" hosts_try_chunking = 198.51.100.1 create directory /etc/virtual/ Inside this directory create this 3 files: "smtp_active_hostnames" with following content: aaa.aaa.aaa.aaa: mail.hostname_for_domain_a bbb.bbb.bbb.bbb: mail.hostname_for_domain_b ccc.ccc.ccc.ccc: mail.hostname_for_domain_c "helo_data" with following content: aaa.aaa.aaa.aaa: mail.domain2.com bbb.bbb.bbb.bbb: mail.domain3.com ccc.ccc.ccc.ccc: mail.domain4.com "domainips" with following content: domain_a: aaa.aaa.aaa.aaa domain_b: bbb.bbb.bbb.bbb domain_c: ccc.ccc.ccc.ccc Hope it helps

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