Your daemon doesn’t write to his logfile after rotating log using newsyslog? You are executing a postrotate command in newsyslog.conf?
The reason for this strange behaviour is that in case of executing a postrate command per definition (rtfm newsyslog.conf) no SIGHUP will be sent to syslogd.
Solution: execute a pkill -HUP syslogd afterwards:
#/var/log/maillog 640 7 1 * Z /var/log/maillog 640 7 1 * Z "/usr/bin/tailkick /var/log/maillog;pkill -HUP syslogd" /var/log/mailcontrol/mailcontrol.log 600 8 * $D0 Z