Shoutbox

The port 80 cannot be used probably because there is a web server running on it. So, you'll have to use 'passive mode' to send files. In that mode, it doesn't matter your connection settings (port and IP detection), because it will use your friend's settings, thus he must have an open port and a valid external IP address.

If he's behind a proxy or a connection that blocks inbound requests (i.e. if he cannot send you files too), then you won't be able to send files, unless you find an open port (or shutdown the webserver to use port 80). In that case, you won't need the passive mode anymore (just set the correct options for your connection).

If not, then you have to use passive mode and he must open a local TCP port for inbound traffic in his firewall/etc (like 8030), and set his correct internet IP (the 'detect automatically' should work fine) to support your transfer request.

Let me know if it worked