Postfix and Spamassassin don't start on boot after Ubuntu 16.04 upgrade
Solved: The missing piece was
systemctl enable spamassassin.service
Ubuntu 16.04 uses systemd so you need to change your commands to the systemd versions. On systemd systems you use ...
systemctl COMMAND SERVICE
This to list all available services:
systemctl list-units --type=service --all
So for postfix that would be ...
systemctl start postfix.service
And logging is done with
journalctl -u postfix
Same applies for spamassassin.