subscribing to list ? a friend in need

[drded@ix.netcom.com (David Deutsch)]

I was just visiting Bob Kilpatrick of Former Glory Racing in New Haven, 
CT and trying to get him subscribed to mgs digest. I got back a message 
saying that another message was needed using a "authorization key" WHAT 
DOES THIS MEAN ? Please advise and I will e-mail him (or CC him with 
your reply at FMRGLRY@aol.com) .