[rrao]

grandpajim,
Do you get Zimlet installed successfully? At least on windows,

1. 
To start with, You must be running Zimbra Desktop

2. 
CD to..
C:\Documents and Settings\<USERNAME>\Local Settings\Application Data\Zimbra\zdesktop  (assuming that this is where zdesktop is installed)

3. 
 java -cp jetty\lib\log4j-1.2.8.jar;jetty\common\lib\commons-httpclient-3.0.jar;jetty\common\lib\mail.jar;jetty\common\lib \commons-logging.jar;jetty\common\lib\commons-codec-1.3.jar;jetty\common\lib\json.jar;jetty\common\lib\dom4j-1.5.jar;jetty\common\lib\zimbracommon.jar;jetty\we bapps\service\WEB-INF\lib\zimbrastore.jar -Dzimbra.config=conf\localconfig.xml com.zimbra.cs.zimlet.ZimletUtil deploy zimlets\<ZIMLET.zip>

4.
stop service by clicking on the systray icon

5. Start Service

===========================================
If the email reminder zimlet itself isnt working(i.e. throwing some error), then please undeploy it and re-download the latest

(version 0.3)

that was uploaded couple of minutes back from gallery.

To undeploy..
all the steps are similar to deploy but the 3rd one.

 java -cp jetty\lib\log4j-1.2.8.jar;jetty\common\lib\commons-httpclient-3.0.jar;jetty\common\lib\mail.jar;jetty\common\lib \commons-logging.jar;jetty\common\lib\commons-codec-1.3.jar;jetty\common\lib\json.jar;jetty\common\lib\dom4j-1.5.jar;jetty\common\lib\zimbracommon.jar;jetty\we bapps\service\WEB-INF\lib\zimbrastore.jar -Dzimbra.config=conf\localconfig.xml com.zimbra.cs.zimlet.ZimletUtil undeploy ZIMLET-name-without-zip-or-path

for example..

 java -cp jetty\lib\log4j-1.2.8.jar;jetty\common\lib\commons-httpclient-3.0.jar;jetty\common\lib\mail.jar;jetty\common\lib \commons-logging.jar;jetty\common\lib\commons-codec-1.3.jar;jetty\common\lib\json.jar;jetty\common\lib\dom4j-1.5.jar;jetty\common\lib\zimbracommon.jar;jetty\we bapps\service\WEB-INF\lib\zimbrastore.jar -Dzimbra.config=conf\localconfig.xml com.zimbra.cs.zimlet.ZimletUtil undeploy com_zimbra_emailreminder

Edit by mmorse:
v3 for both Email Reminder & Birthday Reminder for Zimbra Desktop usage are in the gallery.