Thanks for the reply!
Mostly, the log is full of:
mail postfix/proxymap: fatal: unsupported dictionary type: mysql
mail postfix/smtpd: warning: premature end-of-input on private/proxymap socket while reading input attribute name
mail postfix/smtpd: warning: private/proxymap socket: service dict_proxy_open: Success
mail postfix/master: warning: process /usr/libexec/postfix/proxymap pid 14645 exit status 1
mail postfix/master: warning: /usr/libexec/postfix/proxymap: bad command startup -- throttling
Message group repeats about once every minute.
Did you install ISPConfig on the same machine? This doesn't work, the virtual Postfix setup is incompatible with ISPConfig!
Ouch! It would have been nice had there been a note in the tutorial to that effect. The postfix/courier/mysql how-to simply said to set up a Fedora core 5 machine per that howtoforge how-to - which included instructions for ISPconfig. It sounded like a good idea, so I did. Is there an uninstall how-to for ISPConfig?