Due to repeated challenges with random messages being rejected by subscribers' mail providers (from DMARC invalidations, lines too long to be forwarded, content misidentified as spam, et cetera), the time required for list administrators to manage the resulting extra work is greater than the benefit we get from Mailman being able to figure out when subscriber addresses become defunct. As such, I've disabled the "bounce processing" feature for the time being, until we can work out solutions to make it less of a burden on our list admins and less confusing/failure prone for the list subscribers. If we do decide to give it another try at some point in the future, after some of the current challenges with it get ironed out, I'll let the list know. -- Jeremy Stanley