the crontab is not missing, you can see below:
[root@mail ~]# su zimbra
[zimbra@mail root]$ crontab -l
# ZIMBRASTART -- DO NOT EDIT ANYTHING BETWEEN THIS LINE AND ZIMBRAEND
#
# Log pruning
#
30 2 * * * find /opt/zimbra/log/ -type f -name \*.log\* -mtime +8 -exec rm {} \; > /dev/null 2>&1
35 2 * * * find /opt/zimbra/log/ -type f -name \*.out.???????????? -mtime +8 -exec rm {} \; > /dev/null 2>&1
#
# tmp dir cleaning
#
40 2 * * * /opt/zimbra/libexec/zmcleantmp
#
# Status logging
#
*/2 * * * * /opt/zimbra/libexec/zmstatuslog > /dev/null 2>&1
#*/10 * * * * /opt/zimbra/libexec/zmdisklog > /dev/null 2>&1
#
# SSL Certificate Expiration Checks
#
0 0 1 * * /opt/zimbra/libexec/zmcheckexpiredcerts -days 30 -email
#
# Backups
#
# BACKUP BEGIN
# BACKUP END
#
# crontab.ldap
#
#
#
# crontab.store
#
# Log pruning
#
30 2 * * * find /opt/zimbra/mailboxd/logs/ -type f -name \*log\* -mtime +8 -exec rm {} \; > /dev/null 2>&1
30 2 * * * find /opt/zimbra/log/ -type f -name stacktrace.\* -mtime +8 -exec rm {} \; > /dev/null 2>&1
#
# Report on any database inconsistencies
#
0 23 * * 7 /opt/zimbra/libexec/zmdbintegrityreport -m
#
# Monitor for multiple mysqld to prevent corruption
#
*/5 * * * * /opt/zimbra/libexec/zmcheckduplicatemysqld -e > /dev/null 2>&1
#
# Check zimbraVersionCheckURL for new update.
# Only runs if this server matches zimbraVersionCheckServer
# Only executes on zimbraVersionCheckInterval. min 2h interval
#
18 */2 * * * /opt/zimbra/libexec/zmcheckversion -c >> /dev/null 2>&1
#
# crontab.logger
#
# process logs
#
00,10,20,30,40,50 * * * * /opt/zimbra/libexec/zmlogprocess > /tmp/logprocess.out 2>&1
#
# Graph generation
#
#10 * * * * /opt/zimbra/libexec/zmgengraphs >> /tmp/gengraphs.out 2>&1
#
# Daily reports
#
30 23 * * * /opt/zimbra/libexec/zmdailyreport -m
#
# crontab.mta
#
#
# Queue logging
#
0,10,20,30,40,50 * * * * /opt/zimbra/libexec/zmqueuelog
#
# Spam training
#
0 23 * * * /opt/zimbra/bin/zmtrainsa >> /opt/zimbra/log/spamtrain.log 2>&1
#
# Spam training cleanup
#
45 23 * * * /opt/zimbra/bin/zmtrainsa --cleanup >> /opt/zimbra/log/spamtrain.log 2>&1
#
# Dspam cleanup
#
0 1 * * * [ -d /opt/zimbra/data/dspam/data/z/i/zimbra/zimbra.sig ] && find /opt/zimbra/data/dspam/data/z/i/zimbra/zimbra.sig/ -type f -name \*sig -mtime +7 -exec rm {} \; > /dev/null 2>&1
8 4 * * * [ -f /opt/zimbra/data/dspam/system.log ] && /opt/zimbra/dspam/bin/dspam_logrotate -a 60 -l /opt/zimbra/data/dspam/system.log
8 8 * * * [ -f /opt/zimbra/data/dspam/data/z/i/zimbra/zimbra.log ] && /opt/zimbra/dspam/bin/dspam_logrotate -a 60 -l /opt/zimbra/data/dspam/data/z/i/zimbra/zimbra.log
#
# Spam Bayes auto-expiry
#
20 23 * * * /opt/zimbra/libexec/sa-learn -p /opt/zimbra/conf/salocal.cf --dbpath /opt/zimbra/data/amavisd/.spamassassin --siteconfigpath /opt/zimbra/conf/spamassassin --force-expire --sync > /dev/null 2>&1
#
# Clean up amavisd/tmp
#
15 5,20 * * * find /opt/zimbra/data/amavisd/tmp -maxdepth 1 -type d -name 'amavis-*' -mtime +1 -exec rm -rf {} \; > /dev/null 2>&1
# ZIMBRAEND -- DO NOT EDIT ANYTHING BETWEEN THIS LINE AND ZIMBRASTART |