PostFix Setup problems...

Hello, I'm using centos 7 with cwp and in this step I'm trying to set up PostFix.
In this VPS I will have more than one domain and the main objective is to run mautic.
I am new to the VPS universe so please help haha.



Sorry if I hid something I should not, like I said, I'm new to this universe.
The hostname is pointing to the OVH IP.
RDNS / PTR is also pointing to OVH ip.
But I have this error:

This IP address (ovh ip ex: 195.42.157.187) is associated with the domain (rDNS domain ex: 187.ip-195-42-157.net).
However, your message appears to be sent by (ex: vps584125.vps.ovh.ca).

You need to change the DNS address (PTR type) and the hostname of your server so that both of them have the same value.

Values ​​tested (examples):
 - IP: 195.42.157.187
 - HELO: vps584125.vps.ovh.ca
 - rDNS: 187.ip-195-42-157.net

Could anyone guide me in these steps?

You must set your reverse DNS in OVH.

- Go to your OVH Manager
- Change default reverse name "vps584125.vps.ovh.ca" to your domain of webserver hostname,
For example: "mail.domain.com" and set IP "1.2.3.4"

*) Make sure you already set A record for your reverse domain name.
 

Sorry for the delay to respond and thank you very much!
I'm new to the VPS universe and did not know I had to do this at OVH.
I was able to solve the problem there.

yes, rDNS is a reverse dns for ip address and this can be set only by the ip range owner in your case ovh.
But it also requires that before setup of rDNS that A record at DNS is set for it.