Here's one battle I want to watch from very far away.
Somebody is wrong here.
It's not qmail that's broken. This is true. This brings up a CGI which, if everything checks out, forges the confirmation mail from their address to my fixed majordomo address. Invoked without arguments it brings up a simple form that gives them space to cut and paste those items. All of the direct e-mail approaches work as well, including the mailto URL that might just format the mail for them.