Dear monarch

(...)I don't know why it is called bang.. I thought it was an exclamation mark myself(...)

A few years back, email and news were sent from server to server using a protocol (and program) called UUCP (Unix-to-Unix-CoPy). This used phone lines to push packets of text files from machines that for the most part, were "connected" to the network intermitently, a few times a day.

In those days, email addresses had to include the routing information, telling each system how to forward your message. An email address could have been something like ucbarpa!dino!usb!lem (If memory serves well). Each word in the address would be a host/system/site identifier, as known by the corresponding node. The ! would then instruct said node to "bang" or bounce the file to the next system in line.

As you may easily guess, this system was very awkward (sp?) to use. Later it was entirely replaced with SMTP and NNTP for direct transmission of email and Usenet news from server to server, using the Internet as transport.

During that transition, things were complex because provisions had to be made for rewriting the addresses to RFC-822 format (ie user@site) and for combining RFC-822 and UUCP in the same address, to deal with hybrid or incomplete connections (ie usb!lem@dino.conicit.ve). To this respect, Internet is so much simpler now.

Google for UUCP for more information.