From Zimbra :: Wiki
Here is a step by step instruction of building and deploying a simple Zimlet. It matches the string "Hello World" in the emails, and create a popup balloon that says "Hello World Zimlet". All of these can be done with just a few lines of XML.
First, write the definition file for the Zimlet.
$ cat com_zimbra_hello.xml <zimlet name="com_zimbra_hello" version="1.0" description="Hello World"> <contentObject> <matchOn> <regex attrs="ig">Hello World</regex> </matchOn> <toolTip>Hello World Zimlet</toolTip> </contentObject> </zimlet>
Second, change the owner of the XML file to "zimbra".
Then build a zip bundle of the Zimlet.
$ zip com_zimbra_hello.zip com_zimbra_hello.xml adding: com_zimbra_hello.xml (deflated 42%)
change the owner again to "zimbra".
Now the Zimlet can be deployed to ZCS.
$ /opt/zimbra/bin/zmzimletctl deploy com_zimbra_hello.zip  INFO: Deploying Zimlet com_zimbra_hello in LDAP.  INFO: Installing Zimlet com_zimbra_hello on this host.  INFO: Adding Zimlet com_zimbra_hello to COS default  INFO: Enabling Zimlet com_zimbra_hello
Verify the Zimlet is indeed installed correctly.
$ /opt/zimbra/bin/zmzimletctl listZimlets Installed Zimlet files on this host: com_zimbra_amzn com_zimbra_hello com_zimbra_phone com_zimbra_tracking com_zimbra_url Installed Zimlets in LDAP: com_zimbra_amzn com_zimbra_hello com_zimbra_phone com_zimbra_tracking com_zimbra_url Available Zimlets in COS: default: com_zimbra_amzn com_zimbra_hello com_zimbra_phone com_zimbra_tracking com_zimbra_url
Now the Zimlet is installed. From now on all the new login's will have this Zimlet. If you are already logged in, just hit reload, and this Zimlet will be loaded. Restart tomcat if needed in order to purge the cached COS and Account object in the server.