The DELPH-IN community maintains a number of mailing lists. Subscriptions can be requested from http://lists.delph-in.net/. All regular users of and contributors to DELPH-IN technology are encouraged to subscribe to the developers mailing list available on that page.
Furthermore, there is an active wiki for detailed technical information and community-organized documentation and exchange at http://wiki.delph-in.net/.
General queries about DELPH-IN should be directed to firstname.lastname@example.org.