Digest Subscription

I am having difficulty subscribing to the digest version of this list. I 
followed the instructions on procmail.org and sent an email to 
procmail-d-request(_at_)informatik(_dot_)RWTH-Aachen(_dot_)de , but the email gets bounced 
with an "Unknown or illegal alias" message. How do I subscribe to the digest?


~Dave Greco x121 <dag(_at_)gleim(_dot_)com>