Welcome. hMailServer is a free, open source, e-mail server for Microsoft Windows. It's used by Internet service providers, companies, governments, schools and enthusiasts in all parts of the world. It supports the common e-mail protocols (IMAP, SMTP and POP3) and can easily be integrated with many existing web mail systems.
PLEASE HELP!!!!!!!!! If you have a modem with a built in router, you can use it as a wireless (wifi) router. Wifi doesn't cost money as a service. You just need the devices that are compatible with it. Wifi is just a different way of connecting stuff to the internet.
Even if your PC is not using WIFI a router between the modem and PC is recommended. The cable you linked to would be fine for the connection, but I recommend making it to a router rather than the modem. It will give you ethernet requiring a cable from the modem to the pc, not wifi, as you described.