I am getting error messages from cron every night that say:

Cannot open input file: /opt/zimbra/dspam/var/dspam/data/z/i/zimbra/zimbra.log.in
No such file or directory at /opt/zimbra/dspam/bin/dspam_logrotate line 41.

Subject: Cron <zimbra@mailhost> /opt/zimbra/dspam/bin/dspam_logrotate -a 60 /opt/zimbra/dspam/var/dspam/data/z/i/zimbra/zimbra.log

I checked, and there is nothing on my 4.51 OS installation past /opt/zimbra/dspam/var/dspam ... and that directory is empty.