We run a set of mailinglists for different purposes. Here, you can find out which list does what.
Our main discussion mailinglist. This is how we keep in contact if we don't meet up. It's free for everyone to join, so go ahead and do so.
This list serves as a collection pool for all random or official mail that we get. No discussions here, that's what our discussion list is for.
Our Meetup group has an integrated mailing list as well, but we just use that for announcements, not really for discussions or anything similar.