On the official website of the developers, it's mentioned that the DYMO LabelWriter Add-In for Microsoft Outlook simply works for Outlook and that's it. There is no information regarding the exact version of Outlook supported. Also, the install guide doesn't mention anything about it either which means that you will have to get in touch with the support team in order to find out the exact version of Outlook that's supported.
You can start with the support page: http://www.dymo.com/en-US/online-support
