> There was a Serial ID generated for every participant
Ho did you give the participants the Serial IDs ?
> Is there any way you can provide us with the e-mail addresses and the respective IDs?
This should be possible if the privacy mode of the address entries in the address list was pseudonymous or lower. Send an email with all the details to info@soscisurvey.de, please.
However, please take care of the procedure with the links and eventually with the codes.