i've looked into this a bit and i'm not sure that it is a port blocking problem. i have some modest admin skills, so here is what i did: i installed an irc server on a machine in my home net (which accesses the net via a gateway/firewall). i configured my gateway firewall to port forward to the machine running ircd, then ran a snooper (on the gateway) to watch activity on the port being presented to the world. at first i forwarded 6667 straight through, then tried 443 (https) -> 6667, then tried 80 (http) -> 6667. of course, i had my friend do the same configuration in mirc. the result was, that never was there a single attempt to attach to my gateway. (i also tested all this by using mirc on an outside computer - have two internet legs here.) my friend can always access http and https with a web browser, so those ports cannot possibly be blocked. shouldn't this mean that she should be able to at least connect to the http/https ports on my gateway? is there any possibility that mirc isn't handling some situation that is occurring on her computer?
