Email, Newsgroups and Discussion Lists
- Catalist
Official catalog of list-serv type mailing lists, detailing over 55,000 public lists - Google Groups formerly "Deja News"
Searchable archive of many usenet mailing groups - JISCMail formerly "Mailbase"
Email discussion lists for the UK academic and research communities. Most also have archives - Publically Accessible Mailing Lists
- Topica, formerly "Liszt - the Mailing List Directory"
Directory of emails discussion lists, and newsgroups