I was wondering if there is an easy to use mailing list script which I could use with the Cobalt Raq ?

Thanks.

Raq 4s have an option built-in.

Otherwise, head over to your favorite script archive:
http://www.hotscripts.com
http://www.cgi-resources.com

And look for some programs. If you are planning on managing huge (>10,000) list, look into C/C++ programs as they are generally much faster.