I don't see how this should work. Because to email it, you need to have the data.
Now, you would have to trigger the deletion of the data after the email has been sent. Expression script for example allows you to delete answers to previous questions, but you can only run expression script if the survey isn't completed. And if they survey isn't completed, the email doesn't get sent. So this won't work.
The only way I see would be to trigger the API via an external script through the end url and thus delete the data.
However, I find this kind of behavior "dangerous", because if something goes wrong with sending the email, you'll loose all the data and there is no way to send the email again, without going through the whole evaluation again.
I would rather have a look in the process you have and see if you can prevent via permissions that you can see the results. SOMEONE in the organization must be allowed to see the evaluations, right?
I answer at the LimeSurvey forum in my spare time, I'm not a LimeSurvey GmbH employee.
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