We have released Zimbra Desktop 7.3.1 and we have fixed some of the common issues with ZD 7.3, like the spell check on Windows and the one-click-view attachments::
- https://www.zimbra.com/downloads/zimbra-desktop/
- https://blog.zimbra.com/2017/08/zimbra-desktop-7-3-1-now-available-fixed-spell-check-new-click-view-attachment-workflow/
Please download it and let us know