There are thousands of genealogical mailing lists. Genealogy Resources is a Website index for genealogy mailing lists maintained by John Fullera. He describes and categorizes over 18,000 mailing lists. The first time you need to register and obtain an user name and password. This service is free such as the other mailing list sites.
Every mailing list has two addresses.
The first one has to do with subscribing and unsubscribing. The posting address is the address you send your messages to which you want all other subscribers to read. You will probably get a welcoming letter . Keep this for further use. In some lists you have the opportunity to receive messages as they come or to have them grouped for each day or time period.