Comment # 1 on bug 1167068 from Christian Boltz

# rpm -qlv mailman |grep man/archives
drwxr-x---    2 root    www      /var/lib/mailman/archives
drwxr-x---    2 mailman www      /var/lib/mailman/archives/private
drwxrwsr-x    2 root    mailman  /var/lib/mailman/archives/public

/var/lib/mailman/archives is root:www 750, therefore it shouldn't be a surprise
that mailman can't access it. IMHO mailman:www 750 would make more sense - and
(just tested) after a chown mailman:www the cron scripts work again.

This is probably a regression introduced by
https://build.opensuse.org/request/show/766800

As a sidenote - this SR also introduced

+install -m 0646 -D /dev/null %{buildroot}/var/lib/%{name}/logs/error

mode 0646 looks funny[tm] (but doesn't really hurt because %attr gets the
permissions right)