Log in to Survey. Do not select a survey, but go to "Overviews" and "Unsubscribers" or "Bouncers" in the menu. Here you will find an overview of the unsubscribed e-mail addresses and bouncers.
In the menu go to "Results" and "Net response". Here you can find "Download bounce file".
You can also go to "Communication" and "E-mail management" in the menu. Click on of the e-mail and click on a time of sending. In the column 'bouncer' the option 'download file' is displayed. This file contains all e-mail addresses of the relevant mailing, where it is indicated per e-mail address whether the respondent participated, whether Crowdtech registered the e-mail address as a bouncer and whether the addresses are unsubscribers.