Before diagnosing this issue further, please check whether the Office 2013 installation is the Office 365 Edition:
The Office 365 Edition of Microsoft Outlook 2013 is not compatible with this service. You will need to use a retail version, or alternatively a leased license version (which we can provide). Please contact our sales team for more information on our leased licensing options.
If the Outlook version is not the Office 365 Edition, please perform the following steps to resolve the problem:
- Ensure that the correct version of the Connector is installed (32 or 64 bit) - it must be the same as the office version installed
- Click the "Check for Update" button on the Zimbra tab in Outlook to ensure you have the latest version
- Re-install the Zimbra Connector from http://mirror.neural.net.au/Business%20E-mail/
- Perform a WinMTR trace to check the connection - http://support.neural.com.au/entries/21580904-Running-a-WinMTR-Trace
- Enable Logging in the Zimbra connector, collect the log files and send them in to email@example.com for analysis