Try to connect your PC with ethernet cable to the router (LAN port) and log in to see what's the status of the WAN (Internet) port. You should be able to access router's web interface browsing:...

@roflcopter Don't you have that visual in QoS settings : Try to turn off SPI Firewall and DoS Protection as well and see if that matters:

@Tranas That's pretty unusual behaviour - let's see if @Kevin_Z can give some clue on that.

So, if you enable administrative access to the device (either 443 or 8080) you are able to ping your public IP ? Have you tried to configure virtual server or DMZ, while you have enabled...

If you trust your ISP, that they don't filtering any port, but TCP 25 - that's weird. You can try something unusual - try to set the external port to TCP 80 and test again.

Try to move the external port higher - for example TCP port 60222 and see if that helps: Then try the external access on TCP port 60222. Any intermediate device between your ISP and your router ? Are...