Problem.
I added to /usr/local/psa/etc/logrotate.conf these lines:
/usr/local/psa/var/log/maillog {
missingok
rotate 3
size 100M
compress
}
Some time later /usr/local/psa/etc/logrotate.conf is rotated successfully,
BUT logs are no longer being written in /usr/local/psa/var/log/maillog
(/usr/local/psa/var/log/maillog does not exist or is always empty).