other sites?

Hello Group,
In the past, I've summitted concern and read similar concerns from other members of a general drop in posts and receiving responses to member posts never having received the initial request to the group. 
From time to time I've seen/received posts from the following sites:
research-request@lists.nuestrosranchos.com
owner@lists.nuestrosranchos.com
research@lists.nuestrosranchos.com
Could these additional sites explain the drop in posts?  I'd appreciate it if someone would please explain how they are different from the general, research, and announcement nuestros ranchos sites?  I'm not sure how long they've been in existence and who is privy to their use.  I'd be dismayed if I've been missing any additional research resources available to my group membership.  Thanks so much, Alice