In SmarterMail version 100.0.7067, using FireFox 67.0b16, the Impersonate function on the right of the screen is not working. After selecting a domain name and a user (clicking on the auto-complete suggestion), nothing happens. I have also checked the problem in Chrome to be sure it is not a FireFox problem.

Looking into the Developer console the following error on Angular level occurred:

TypeError: "e.email is undefined"
    impersonate xxxx/interface/output/site-v-100.0.7067.29821.8d6d3c244269800.js:146
    Angular 7