I want to be able to create a web page with a form that will allow users to enter their e-mail and subscribe or unsubscribe from a mailing list / listserv. For example, the following pages have what I’m looking for:
http://www.fsis.usda.gov/News_&_Events/news_release_Subscription/index.asp
and
http://www.srs.fs.usda.gov/compass/compass_esubscribe.htm