I think many people use the sender-field in the simple format with the addr-spec address alone (without "<" and ">") for filters in their mailclients (i know that there is a listid)... With this "fix" the mailman-admin has no chance to set this option on or off and many people will wonder why the filter is not working anymore. i think both is legal with RFC2822 -- i just want to keep that in mind because in my setup i had some problems with the new sender field -- You received this bug notification because you are a member of Mailman Coders, which is subscribed to GNU Mailman. https://bugs.launchpad.net/bugs/736849 Title: Sender header change to improve Outlook To manage notifications about this bug go to: https://bugs.launchpad.net/mailman/+bug/736849/+subscriptions