I used this url when trying:
http://user:
pass@
server:88/service/home/
user/inbox.rss
Substituting italicised sections with real info. Now, this didnt work in a browser either, but if I remove the password stuff from the url and try in a browser, it asks for authentication and then offers me the rss file, trying with and without the password stuff in zimbra fails.
I could be flogging a dead horse here, is this even possible?