Change Incorrect Hostname/mail server

Can someone pls tell me how I can change the hostname or mail server name of a specific website that is being hosted on my VPS via cyberpanel?

I have gone to Logs>>Server Mail and selected Default and saved, but the website in question is still displaying the wrong hostname.

Thanks for any help.

Happy New Year @iamveryok

Your hostname should be in the format of a subdomain (server.iamveryok.com or panel.xxx or anysubdomain.xxxx)

1. Create a website on cyberpanel for this particular subdomain.
2. Issue hostname SSL Cerificate for this subdomain.
3. On your ssh terminal run the folowing as root or admin hostname server.iamveryok.com and check what you set was correct by just running hostname