I managed to get everything working on new mail servers based upon Ubuntu 18.04 and for me at least spam filtering is working much better.  Prior to the upgrade I was getting between 1/3rd and 1/4th of spam in my INBOX rather than spam box, now I am getting 1/25 spams in my INBOX the rest to the spam box and so far no false positives.

     The new servers bring new versions of just about all of the spam control facilities, new versions of spamassassin, postgres, dkim, spf milter, clamav, etc.  It’s still older version of postfix, procmail, and smartlist because I can not get the newer versions to play together well owing to the fact that they each want to operate in their own chroot jail which unfortunately doesn’t give them access to each other which they need to function.  I think eventually I will be able to get the newer version of postfix working but the new procmail is too broken.