You are still able to browse past messages from the ACT and RFT listservs that have occurred prior to the Summer/Fall of 2013, when the listservs were still hosted through Yahoo Groups.
Although both of these Yahoo groups are now inactive, you can download a file containing the complete listserv history from the ACBS website. Follow this link for more information about that option.
(For posts that have occurred after the transition of the listservs to the ACBS website in the Summer/Fall of 2013, you can join the listservs at any time in order to view all posts. In order to join the listservs, please follow the instructions here. Please note: You must be an ACBS member in order to join the listservs.)