We recommend Equine Rescue 101 if you are interested in a moderated discussion list focusing on rescue and with no chit chat or off topic discussions.
The Equine Rescue News is available to rescues who wish to announce horses available for adoption, press releases, fundraisers, stolen horses, etc. It is NOT a discussion list. Anyone may post to it (subject to the guidelines of course) and you need not be subscribed to post or read messages so posts made there get a wide audience.
If you prefer a group that allows off topic emails & chitchat, some have recommended the Horse Rescue Brigate list
There are others out there of course! Some are more focused than others, some are busier than others - I'm sure that there's something out there that meets the needs and tastes of just about everyone and if they don't you can start your own!
Net Posse dedicated to prevention and recovery issues surrounding horse theft.
NetPosse Alerts moderated list for announcements of lost or stolen horses only.
Hooved & Animal Rescue Digest - interactive webzine dedicated to people that do rescue work.
Do Not Adopt List for rescuers to warn each other about potential bad adoptors.
Retraining Thoroughbreds List Info and Archives
ROAN for listings of horses being placed via the Racehorse Outplacement Assistance Network.
Some are discussion lists, some are announce only or moderated lists.
Arizona
Arizona Equine for listing of horses, horse events, and horse related equipment in Arizona only.
Arizona Equine Rescue Resouce forArizonans to find out how to help rescue Arizona horses.
California
TIER - True Innocents Equine Rescue. Gail Garrett's listings of horses available from a Southern California Feedlot.
Lousiana
Louisiana Horses Listing of horses and horse related equipment and discussion of Louisiana issues.
Mid West United States
Central States Equine is for the listing of horses or horse-related items (such as trailers and tack) which are available for sale in the Midwest. All breeds are welcome. This list allows no advertising for commercial services or businesses, it is only for individuals who wish to buy or sell equine or tack in the Central US.
Minnesota
Minnesota Horse Rescue for MN and surrounding states.
North Carolina
North Carolina Equine Rescue League - purpose is to discuss all NC rescue and rehab, whether NCERL is involved or not.
North East
NorthEastRescue equine rescue discussion for the North Eastern United States.
Southwest
Southwest Equine for posting horses and horse equipment for sale and wanted as well as notices about horse related events. It's limited to the Southwestern states - Arizona, Southern California, Nevada, Utah, Colorado and New Mexico.
Texas
Texas Rescue - people involved in all types of animal rescue are welcome.
Lost Pony Texas - dedicated to stolen horse recovery in the state of Texas.
Washington
Equine-L subscription information and archives (must be subscribed to the list to view archives).
Haynet Mailing Lists has most if not all of the various equine mailing lists available.
Jessica Jahiel's Horse Sense Newsletter weekly electronic newsletter on all aspects of horses.
Blind Horse List provides information and support for those horse lovers fortunate enough to own or know a blind horse.
Equine Cushings List from the list home page: "To provide all horse owners who have (or have had) a horse with Cushings disease a place to share experiences, pass along veterinary knowledge or advice, and help each other deal more effectively with the symptoms and problems associated with this disease or closely related syndromes."
Nursemare Mailing List specifically for matching up mares and foals and assisting in raising orphans. You do not have to be subscribed to the list to read the posts, but you do have to be subscribed in order to post any messages.
WESTNILEVIRUS-L is an email discussion group for communication and discussion about West Nile Virus, particularly regarding policy, risk reduction and public education issues. Archives of all postings (except those for which the author requests limited distribution) are posted on this website. WESTNILEVIRUS-L is moderated by Dr. Lois Levitan at Cornell University's Environmental Risk Analysis Program (ERAP). To subscribe, send an email to envrisk@cornell.edu. Include your contact information and the name of this listserv (WESTNILEVIRUS-L) in your message."
Yahoo Groups - a wide variety of lists here. Search horses or your specific breed as they have them rather oddly categorized.
ICQ Home Page - software available in a free beta version that allows you to find friends and folks that share the same interests online. Can chat, send messages and files, play games, etc. There's a "Do Not Disturb" feature just in case you aren't in the mood to chat or are busy sometimes!
Many rescues or rescue sites have bulletin boards on their webpages. These are just a few of the many that are out there.
Animals Needing Homes and Homes Needing Animals - mostly folks looking for free horses, some with horses to sell. Probably something to monitor.
Psalmus Rescue Ads - for advertising rescue horses only.
Retraining the Retired Racehorse - discussion on how to "let down" and train an off the track racehorse.