What settings on a client system can stop access to webserver

[terryd]

I have approximately 50 users at different locations logging onto my website (NT810).
The speed of getting to the login button is acceptable for most, however one site cannot get to the first screen with the login button, nothing happens the system just stays blank until finally a timeout message is sent.

The website is:

 http://webmail.iser.co.za:8088

I have tested this from their system via TeamViewer using both Chrome and IE.
Their settings allow javascript and cookies.
They don't appear to have windows firewall enabled and their antivirus is Avast.

Any suggestions as to what settings could be in place on their system that would prevent them from connecting to the website.
I thought maybe the port number but I am not sure where to check if that is the case.

[kevin plummer]

Hi Terry,

do you swap to https or do you stay in http?

[terryd]

Hi Kevin
Standard http, you can check by using the link.

[Bruce]

my guess would be a firewall, either by them, or by their ISP.

cheers
Bruce

[JPMacDonald]

I agree that it is most likely a firewall issue blocking port 8088 but you might also want to check if it is a DNS resolution issue.

Have them try the site by IP address: http://41.208.210.29:8088

Regards

Parker

ps: forget to mention, I can access the site from here using your original link.

[terryd]

Hi All
Thanks for the feedback. As I mentioned virtually all other users can access the site, just this  one can't. I'll do further checking at their site.