Can connect to the Internet but no mail sites or Entourage!!

Greetings, i have a Macbook Pro 2.16GHZ version 10.4.11 OS X.
I live in bonnie Scotland but am currently on a Drill Ship in Singapore where we have been given access to their wireless network. However, since i handed the Mac over to IT i cannot connect to any mail site, Yahoo, Hotmail etc and any site whereby i have to log in. It just annoyingly tells me " cannot connect to Server"
I don't have a problem surfing the net.
The IT guy says it may be my firewall that is conflicting with their Server which is in Norway.
My firewall is not on, i've cleared my cache, reset safari and tried various other things.
Can anyone help me here as i am close to putting a size 10 thru the IT guys door!!!

Many thanxs

Kev

You mean you have problems with addresses that begin with https:// ?

Yes! I'm quite new to Macs and never noticed the https.
What do you suggest????

It seems the firewall where you are blocks port 443, the HTTPS port. HTTPS use a different port than 80 which HTTP uses.
Can other people on your location reach HTTPS addresses?
Have you tried other browsers than Safari, like Firefox or Opera?
Check to make sure Proxy is not enabled: System Preferences->Network, click Airport and then Advanced. Go to the Proxy server tab. If it says "Configure with PAC", see if the box has a value. If it is set to Manual, see if any of the boxes have an "X" in it to turn it on. If Web proxy or Secure Web proxy is enabled, write down what the value is, then try to remove the check box and OK/Save/Close your way out of the system prefs. Then quit and open Safari.

Let us know how it works out?