I'm not sure if this is an N900 or Zimbra question - my N900 seems to happily sync with my Zimbra setup using the Mail for Exchange stuff.

The only issue is I have to de-select the 'secure connection' checkbox, otherwise I get this message:

"Error: Either Exchange server requires secure connection or account is disabled".

I think it might be related to this bug: https://bugs.maemo.org/show_bug.cgi?id=6582 but I'm just wanting to check and see if anyone else has experienced this issue?

Thanks