I prefer to use English-based application GUI's but with localized date and number formats. other users may prefer fully localized GUI's.
I gather the quickest way to do within zimbra is to add a "new language": duplicate and modify the english messages files at /opt/zimbra/jetty/webapps/zimbra/WEB-INF/classes/messages
for example I18nMsg.properties is copied to I18nMsg_gdm.properties
Where must I now add the new language (location of the definition file) so can I chose it in the preferences of the webclient?