If a non-spam message accidentally gets discarded, just do:
cat /var/lib/mailman/spam/not-really-spam.msg | /usr/lib/debbugs/receive
+chown Debian-debbugs:Debian-debbugs /var/lib/debbugs/spool/incoming/*
... check it works ...
mv /var/lib/mailman/spam/not-really-spam.msg /var/lib/mailman/not-spam/
+Also check that the sender was not added to the auto-discard/reject list
+in the debbugs-submit Mailman interface.
+
** Administrivia
The debbugs-submit list should have the administrivia option off,