Thunderbird - Reply to Mail List

Tue Feb 27 14:45:46 CET 2007

I feel really stupid asking this, but I am having troubles using 
Thunderbird. I receive the list in digest mode. For each digest, it 
will show up as a single messages in my inbox. Also for each digest it 
will have each individual message as an attachment. But I cannot find a 
way to respond to an individual message. If I open one of the 
attachments (ie individual message), it will not let me reply (can click 
the reply button, but nothing happens).
I was thinking this should be a very easy thing to do (and other mail 
clients make this easy), but I am pretty much stumped. Any thoughts?