You have two possibilities when replying to a message received from the listserv:
1. You can send your reply to the listserv for everyone to see. 2 You can reply privately to the original sender of the message.
The CinSUG listserv currently follows the default choice for all lists at Freelists.org. If you hit "Reply" in your mail client, the reply will be addressed to cinsug@xxxxxxxxxxxxx and will be sent to everyone on the list. The reply will NOT be addressed to the person who posted the original message, even though that person is listed in the "From:" field in the email header. If you expand the headers in your email client, you will see that the "From:" and "Reply-To:" fields are different.
If you want to reply to the sender privately, you must extract the sender's email address from the header and manually address the reply to the sender.