I-World - Internet Services and Information Management
One popular e-mail list program is called "Majordomo". Several files are available to help list owners and users. The basic help file explains the commands majordomo understands. List owners can use some additional commands, which are described in this new list owner mailing. There is also a document explaining how to configure a list to function the way you would like it to.
More detailed technical and user documentation can be obtained from the 'greatcircle' site, home of Majordomo.
Some excellent information on owning and maintaining a list can be found in UC Berkeley version of the list owners guide.
There is also a Majordomo FAQ available.
For administrators wanting to configure majordomo for use with different domains hosted virtually here is a description of how to do it.