Ok, forwarding from OTRS to mailing lists should now work correctly.
The problem was that when OTRS (along with
secure.wikimedia.org) was moved from
our main mail server to a second box, the mail configuration on that second box
wasn't quite right.
It thought that it controlled mail for the entire wikimedia domain, which it
doesn't. As a result, mails forwarded to the lists got handled on the wrong
server, where they fell into a deep black hole never to be seen again.
I've tweaked the config so it knows it handles only OTRS, and other mails are
forwarded properly through the main mail server.
-- brion vibber (brion @
pobox.com)