Clients cannot login to there control panel

[annmariei]

Hi
I am very new to this and I have read the user guide on this but cannot find my issue. Basically I have a vps with the hostname set to hostname.webology.com i have an entry into my hostname file so i can login to plese using ip, hostname etc when i gave the link to my client www.theirdomain.co.uk:8443 they cannot access the page it times out.

If i put an entry in there host file to resolve the hostname to ip they can access the page. What can i do instead, I do not want to be changing all of my clients host files etc. I am probably very dumb im assuming its something to do with dns and namedservers etc

Please help thank you in advance