The easiest way would probably be to give them a mailto URL pointing
to the listname-subscribe-request address, ie,
You can subscribe to the MYLIST-L list by clicking
<a href="mailto:[log in to unmask]">
here.</a> (If your mail program does not support clickable address
links, simply send a blank mail message to mylist-l-subscribe-request@
myserver.example.com to obtain a subscription.)
This requires 1.8d.
Nathan