Can you access your SME using its local IP on the LAN and serve the webpages using a browser ?
If yes then the problem is not SME.
port forwarding only work from the outside or wan side of a router. Again you can not hit your sme with externalIP:whateverport from inside your lan... This is simply a limitation of NAT, it is impossible to do , see this thread
https://supportforums.cisco.com/discussion/11262681/nat-port-forward-doesnt-work-inside-lan as an example. As long as you do not understand this, you will not be able to go further.
If you want to test your connection port forwarding you will have to do this from outside with your phone connection ( not connected with wifi on your lan of course) or from elsewhere. All test you do from inside will fail and end up in a loop.
This will be the same with your domain name unless:
- your sme has the domain defined as local and act as dhcp for all your computer
- your router act as dhcp server for lan and is evolved to handle split dns and point the domain to your sme ( not probable)
- you defined your local sme ip as associated to your domain on all hosts files of all your computer
But again from inside you wiill be able to access to you sme with port 80 only for webserver, unless you also define in the sever manager a port forward 8080 to 80 on localhost, which is for the moment as useless as creating on your modem router the forward of 8080 to 80 fo the lan ip of your sme.
The only step you should try from now are:
- as told by Janet, contact your ISP to have the level 2 support so they will be able to answer technical question rather than having somebody reading a script.
- only do a port forward on your modem router from 80 to 80 direct to the LAN IP of your SME, Then go outside of your lan, and try to connect from outside to your internet ip on port 80 with sme on and its ip being the same as given in the router for port forwarding.