Listserv to Nabble works, Nabble to listserv does not

[Mark W. Kidd]

I am the administrator of a Mailman 2.1 listserv that I am integrating with Nabble.

Everything seems to be working except that messages posted to the Nabble forum do not seem to be sent to the listserv (or they are not arriving?)

Messages sent to the listserv appear as expected in Nabble. I can confirm that the Nabble address is subscribed to the list.

Can anyone suggest a solution or the next step to troubleshoot?