As an emergency measure, the Mailman and email service on the Mailman server were shut down for several hours to prevent further subscription spam from further worsening the server's IP reputation.
Additional measures have been put in place and Mailman and email service on the Mailman server were re-enabled this morning.
Mailman: Stopped 19th July at 13:22
Exim4: Stopped 19th July at 14:20
Exim4: Started 20th July at 09:38
Mailman: Started 20th July at 10:10