Azure & Centos 7 & Centos I try to setup mail service but rDNS/PTR check for IP 10.0.0.4 = not found

Question

I am trying to setup the mail service in centos webpanel. But the setup says rDNS/PTR check for IP 10.0.0.4 = not found!

Is there anyone who can help me?

This is what it gets:

rDNS/PTR = FAILED, check with your hosting provider! FAILED [Check SenderBase] rDNS/PTR check for IP 10.0.0.4 = not found!

Answer 1

10.0.0.4 is a non-routable IP, they are supposed to be used for internal use.

You will need to have a valid public IP address.

These ips are for NAT's and for that reason are non-routable
or ISPs will not make routes for this ip addresses.

192.168.x.x
172.16.x.x
10.x.x.x

No public DNS will resolve to this ip addreses if you want to use it in your internal network you will have to use your own DNS server but notice that will be unable to send and receive emails to the internet or other mail servers.

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