rDNS record for a Private IP

Good morning,

I have been naded an unusual issue, at least in my experience.

We have extremely important emails being sent from the UK via an MPLS setup, and they are using Private DNS entries. Our SPam and Email servers require rDNS or the emails are blocked. We whitelisted and IP address for them yesterday but that did not seem to help.

This has been escalated to top priority as these emails are for our CEO and COO. What can I do from my end to ensure that the emails can be received and delievered?

I have about four hours to correct this as the senders are on UK time and I am on EST time, so if anyne can help me I would be most gratefull.

Thanks
Matt
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newmanmeNetwork Administrator\EngineerAsked:
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MaheshConnect With a Mentor ArchitectCommented:
ask sender company to create reverse dns entry at their ISP end for public IP which is sending outbound emails
Check their message header at your end and check "hello" server entry name and its public IP corresponding to that company
Only IP owner (ISP) can create reverse dns entry
Ex: smtp.domain.com is the entry you received in header against public IP x.x.x.x)

In that case if I ping "ping -a x.x.x.x) it should resolve to smtp.domain.com and vice versa

now your exchange server will pass sender based on rDNS entry
OR
they should have valid SPF record which will allow exchange to validate and allow email from that sender

Check online
https://www.debouncer.com/reverse-dns-check
http://www.dnsqueries.com/en/reverse_lookup.php
https://postmaster.aol.com/rDNS
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newmanmeNetwork Administrator\EngineerAuthor Commented:
Good afternoon,

I apologize I have not checked back here to see your response.

It turns out that when we switched from the VPN to the MPLS that the DNS entry needed was on a server we no longer had access to.

Thank you for your response, I am giving you credit since no one else responded.

thanks
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newmanmeNetwork Administrator\EngineerAuthor Commented:
Good afternoon,

I apologize I have not checked back here to see your response.

It turns out that when we switched from the VPN to the MPLS that the DNS entry needed was on a server we no longer had access to.

Thank you for your response, I am giving you credit since no one else responded.

thanks
0
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