OpenBSD | newsyslog | postrotate command

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