mailbox: Stopped

[iceruam]

I tried to log into zimbra this morning to get my mail to no avail. I restarted zimbra and all was well. I was wondering where I could start looking to see why? version 4.5.6
it stopped.
My message log:
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: antispam: Running
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: antivirus: Running
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: ldap: Running
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: logger: Running
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: mailbox: Stopped
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: mta: Running
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: snmp: Running
Aug 22 21:22:07 zmail zimbramon[2462]: 2462:info: 2007-08-22 21:22:01, STATUS: zmail.mydomain.com: spell: Running
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: antispam: Running
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: antivirus: Running
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: ldap: Running
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: logger: Running
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: mailbox: Stopped
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: mta: Running
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: snmp: Running
Aug 22 21:24:06 zmail zimbramon[2782]: 2782:info: 2007-08-22 21:24:01, STATUS: zmail.mydomain.com: spell: Running

[mmorse]

The big ones: /opt/zimbra/mailbox.log & /var/log/zimbra.log
Once you get an idea from those check these locations: /docs/ne/latest/administration_guide/9_Monitoring.12.1.html#1075561