How to change the VPS server hostname?

[RadioKing]

When I setup Sentora I set it up on the sentora.domain.com subdomain and I have issues with mail clients to find server! How would I go about fixing this? All other works fine, even in WebMail. All mails in WebMail works pretty good. Also my server name is not visible on Hostname LookUp too!  

When I spoke with support where I took a VPS server they wrote me this:

"The hostname was set within Sentora as this is what is managing the hostname. You should find in the configs that it's set to "sentora.domain.com" and it should be just domain.com. Once that's done you'll be good to go."

Is it possible to fix it without reinstalling Server or Sentora to get right server name domain.com? Please help!!! Thanks!  

[Me.B]

Open the /etc/sysconfig/network file with your favorite text editor. Modify the HOSTNAME= value to match your FQDN host name.

[horizon]

Its not quite as easy.

If you are sending emails some recipient servers check the server name is the same as the
reverse name lookup of the IP address you are using. This is an anti-spam/fraud check

You need to get the owner of the IP, your service provider, to change that to be the same
as the name you give the server.

[Me.B]

For IP reverse you need to contact hosting provider and they will tell how to do that usually.

For example this is how to for OVH:

http://help.ovh.com/PersonalisedReverse

[ryucz]

AND Your reverse DNS MUST be same as the system uses in SMTP HELO and banner.