The information is in the message headers, I have learned:

List-Post: <mailto:kwiki@perl.org>
List-Help: <mailto:kwiki-help@perl.org>
List-Unsubscribe: <mailto:kwiki-unsubscribe@perl.org>
List-Subscribe: <mailto:kwiki-subscribe@perl.org>
List-Id: <kwiki.perl.org>

Perhaps this information should be at the bottom of each email. I don't 
routinely view detailed header information in email on Thunderbird; I 
wonder how many people do? Not many, I bet.

Thanks very much for the assist and again please pardon this email,

Dave Baker