I recently had to rebuild my server and decided to go with The Perfect Server - Ubuntu 15.10, but I fear I am beginning to regret my decision after having no issues with 14.04. I simply cannot get Mailman to either deliver mail to list members or archive postings and despite the settings it seems to accept mail from any address (not just subscribed) - it does however seem to send mail to the list owner, but that's about all. I have checked perms, aliases and they look good, the mail log doesn't seem to show anything that will help. I have googled until the cows come home, but trying to follow the threads on python.org and gnu.org, I end up going in circles. Can someone point me to a good starting point to debug what is happening?