I fixed this problem. In my case it had to do with booting from a SSD, and not all services had completed their startup when postfix was started. Please see:
https://askubuntu.com/questions/929407/postfix-problem-when-started- from-ssd/931070?noredirect=1#comment1505997_931070 It looks like I was on the right path to solving my Postfix problem. I ended up changing this: ~$ cd /etc/systemd/system/postfix.service.d ~$ more override.conf [Unit] After=network-online.target After=systemd-resolved.service To this: ~$ cd /etc/systemd/system/postfix.service.d ~$ more override.conf [Unit] #After=network-online.target #After=systemd-resolved.service -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1627117 Title: After systemd integration enabled, Postfix will no longer send mail on startup To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/postfix/+bug/1627117/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
