Version 3.1.1-9 of mailman3 is marked for autoremoval from testing on Sat 12 May 2018. It depends (transitively) on uwsgi, affected by #894363, #894624. You should try to prevent the removal by fixing these RC bugs.
Last update: 2018-04-25
Depends on packages which need a new maintainer
The packages that mailman3 depends on which need a new maintainer are: