/etc/cron.daily/logrotate: (Mail Error Message)

[erdem012]

What is the problem ?

Mail Subject : Cron <root@mail> test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
Mail Body:
/etc/cron.daily/logrotate:
error: error creating output file /opt/zimbra/log/zmlogswatch.out.1: File exists
error: error creating output file /opt/zimbra/log/zmswatch.out.1: File exists
error: error creating output file /opt/zimbra/zmstat/zmstat.out.1: File exists
run-parts: /etc/cron.daily/logrotate exited with return code 1