We're using the version 7.1.2 zcs and would like to use this zimlet! But on our testenvironment we could not export the exported messages. Everthing work great but when we select the checkbox "Export messages (created a .tgz file)" it does nothing after pressing "Archive" ..
So maybe you are not interested to use it in 7.1.2 but it will be a great idea, because there is nothing else to 'archive" messages :(
(if this will work you will get a 5 star rating :P )