There are several Indico-related mailing lists that you can subscribe to or read the archives of.

project-indico-announce@cern.ch

Low-volume read-only mailing list to announce new Indico releases and other major news concerning the project. Every Indico user is strongly encouraged to subscribe to this list.
Moderated: yes

project-indico-usergroup@cern.ch

Possibly high-volume mailing list, intended for discussion among users and administrators of Indico.
Moderated: no

project-indico-devel@cern.ch

Possibly high-volume mailing list, intended for discussion among Indico developers and hackers.
Moderated: no

project-indico-administrators@cern.ch

Possibly high-volume mailing list, intended for discussion among Indico server administrators (installation problems, bugs, tech questions...).
Moderated: no

If you want to unsubscribe, please contact to helpdesk_at_cern.ch.