I tried to download the mobile client. The download is broken. I only get a very small .jad file (638 bytes). I tried different browsers on desktop, mobile browser, different location.
Edit
The jad files are some kind of redirector and my phone E71 doesn't like it (invalid). I did manage to install it by downloading the jar file from
http://www.testzimbra.com/zimbrame/j..._US-0.9.34.jar . It works.