Antivirus
Zimbra uses the ClamAV engine for antivirus.
Options to control anti-virus from the CLI:
[zimbra@server]$ zmclamdctl Usage: /opt/zimbra/bin/zmclamdctl start|stop|kill|restart|status
So antivirus is not running.
It might be because its downloading the antivirus database, so give it 1 min. If thats not it, try this:
[zimbra@mail root]$ zmcontrol status Host mail.domain.com antispam Running antivirus Stopped zmclamdctl is not running ldap Running logger Running mailbox Running mta Running snmp Running spell Running