You can subscribe to the list in mail mode by sending a message to NDDUNNemail@example.com that contains the word
and nothing else. If you prefer digest mode, send the command instead to NDDUNN-Dfirstname.lastname@example.org.
To unsubscribe, send the command "unsubscribe" to NDDUNN-Lemail@example.com (if in mail mode) or NDDUNN-Dfirstname.lastname@example.org (if in digest mode.)
To switch from one mode to the other, unsubscribe from one and then subscribe to the other. There is no "no mail" mode -- if you want messages to stop, you should simply unsubscribe.
To post to both NDDUNN-L and NDDUNN-D, messages should be sent to NDDUNN-L@rootsweb.com. Messages sent there will appear both places.