Same thing here -- on Mac OSX, 0.58 doesn't show any Mail tab, and periodically spits out "no properties" error window. If it did "Send Report" or something, pls check your mail.
It looks like 0.58 only works with 5.0 server but not 4.5. Something is broken in compatibility. We are investigating. Thanks for all of your feedback!
We found the cause of the issue. Because most people inside of zimbra are using zdesktop with 5.0 server by now, this didn't get caught in time. Apologies for wasting everyone's time. We are working on a fix and keep folk posted on release data. Thanks for your help!