"We have scheduled an upgrade of mailman (
https://lists.wikimedia.org) for:
Wednesday, September 9, 2015 at 2:00:00 PM UTC ( 7:00 AM PDT, 16:00 CEST)
The scheduled mainteance window is 4 hours (or less).
During this time please expect all the mailing lists (web interface
and email) to be down."
Full details at:
https://lists.wikimedia.org/pipermail/listadmins/2015-September/000077.html
Regards, Richard.