Hi - I made an experimental configuration change on sourceware/gcc.gnu.org yesterday that had unforeseen effects on some mailing list subscribers. We turned on VERP (variable envelope return paths) on outgoing mail from mailman, in order to assist tracking mail delivery problems. This changes the Sender: field that allows precise handling of bounces, but interferes with filtering on that field.
If you use Sender:-based filtering for sorting your incoming email stream, I suggest switching to observing List-Id: instead, or else using a regexp/substring style of Sender: matching. We're not sure we're keeping the new configuration yet. It's performing well. With either of the two changes, you would be immunized against change even if we return to the previous configuration sometime. I'm sorry about the inconvenience! - FChE
