I forgot to mention this to you earlier, but you can greatly reduce the config, if you just use 1 UserParameter like this:

UserParameter=zimbra[*],/etc/zabbix/check_zimbra.sh $1

Then you can just create items like zimbra[antivirus] instead of zimbra.antivirus and you don't need to change the zabbix_agentd.conf file if you add new checks :)

Greets,

Bart