Archivum.info
- Large archive of mailing lists and newsgroups.
- http://archivum.info/

openSubscriber
- A mail-to-web gateway with searchable archives of public mailing lists.
- http://www.opensubscriber.com/

CataList
- The official catalog of LISTSERV lists.
- http://www.lsoft.com/lists/listref.html

I Want Newsletters
- A large collection of free newsletters sorted by category.
- http://www.iwantnewsletters.com/

Dolist.net
- References all mailing list types, discussion, diffusion, newsletter, e-zine, alert bulletin, and newsgroups.
- http://directory.dolist.net/annuaire_en.asp

Public Mailing Lists Managed by Arrow
- A frequently-updated list of publicly accessible mailing lists managed by users of Roger Smith Software's Arrow Mailing List Server.
- http://www.jadebox.com/arrow/list.html

listTool
- A directory of lists that includes an easy way of subscribing and unsubscribing to them.
- http://www.listtool.com/

Email Newsletters & Ezines at Tile.net
- Large mailing list directory.
- http://tile.net/lists/