Automatic mailing lists are just like normal mailing lists, except that you can subscribe and unsubscribe to them automatically as well as manually.
Subscribing to automatic mailing lists
Send an e-mail to the e-mail address "list-server@domain" with
the subject line "subscribe<space>mailing-list-name". The body
is irrelevant and will be ignored.
Unsubscribing from automatic mailing lists
Send an e-mail to the e-mail address "list-server@domain" with
the subject line "unsubscribe<space>mailing-list-name". The body
is irrelevant and will be ignored.