Mailing lists are email based discussions. You can ask for support using the GNOME mailing lists. Almost each GNOME application has its own mailing list. The complete list of mailing-lists are listed at.
You may need to subscribe to the mailing-list before being able to send an email to it.
The default language used on mailing lists is English. There are user mailing lists for other languages. For example, gnome-de for German speakers or gnome-cl-list for all things related to Chile.