Hm, my Antivirus don't finding any viruse.
I send through zimbra test email with file eicar.zip and zimbra do not block it.
When I try to send it outbound over my frontend relay (exim+clamav) - my message is blocked by ClamAV.

said: 550
ClamAV found a virus: Eicar-Test-Signature (in reply to end of DATA
command)

zmprov gs `zmhostname` zimbraServiceEnabled
# *****
zimbraServiceEnabled: antivirus
zimbraServiceEnabled: logger
zimbraServiceEnabled: mailbox
zimbraServiceEnabled: memcached
zimbraServiceEnabled: mta
zimbraServiceEnabled: stats
zimbraServiceEnabled: snmp
zimbraServiceEnabled: ldap
zimbraServiceEnabled: spell