I've checked the website and the software. I've also installed the application on my computer, but there is the problem: it's not specified regarding compatibility with certain Outlook versions. On the official website, you can see that it supports Outlook but it doesn't say which versions. If it's not working on Outlook 2016, then it means MSGTag Status needs an update from the developers.
You can give the feedback at http://www.msgtag.com/contact/