Hey,
ok, if port 80 can't be seen I'm guessing people form the outside can't see your web site either.
But if you have managed to the web mail then I'm guessing the server it working, just not able to be seen by the outside world.
Check this address:
http://192.168.0.10 (that will show you if port 80 can be seen from the inside)
This can be one or all of a couple of things.
1. Your D-Link Router isn't forwarding through properly
2. Your ISP is blocking these ports for one reason or another.
Luckily I have a D-Link router and so my setup will be similar.
So I would presume the problem is not with your SME box, but further down the line, so building up another box will not fix it.
From your D-Link Router, can you send me the details on all the items ticked in your virtual server list, and I'll make sure that is right.
I know this can be frustrating, stick with it I think your almost there, and I'll try to get back to you sooner next time.