For supporting and lifetime subscribers the PinballX and GameEx FTP the details are as follows.

Server: online.gameex.com
Port: 21 (Default).
User: Your username for these forums (same for GameEx Online).
Password: Your password here

Non subscribing members can browse the FTP server and upload on port 22.

Note: This is an FTP server not a web server and a suitable FTP client is required. The free FTP client Filezllla is good choice.

If you simply wish to browse and see what is on the FTP (without downloading) look here:
http://ftpbrowse.gameex.com