a) not sure why my header is "suspicious" b) I'm not even signed up for the Infrastructure mailing list.
Some moron is gating the messages sent through this and the other Drupal mailing lists to the infrastructure list. As a measure against this spam, somebody has configured the infrastructure list to not accept mails that have some header that is introduced by the gating software. If that somebody could just swicth off the receipts that mailman sends for not accepted messages all would be reasonably fine.
That someone would be me. I tried to identify the culprit so I could unsubscribe him, but failed to track him down. As such, I blocked the sender based on other metrics. I didn't realize we were sending out these messages to non-administrators. I made some configuration changes now so hopefully, everything is well now. If not, let me know and I'll fiddle with it some more. ;-) -- Dries Buytaert :: http://www.buytaert.net/