You can try and run a web service to post the email ids to a private server, this way you will have a list of people who have completed your survey, but not connected to their responses.
Since, I still haven't come across a proper solution to remove identifiable information from the survey, I use a complicated process. It may help:

1. Create an embedded variable:

   eml-asked



2. Set its value as

   "false"

   .


3. Create a Question Block that asks for an individual's email id. Lets call it

   eml-block

   . (It can be a question, but we need a page break somewhere, so block is better)


4. Add JS similar to the one below. It tracks if the question has been displayed earlier or not. And hides the question along with removing the email id, if it is displayed more than once.


5. Place

    eml-block

   in the survey flow


6. Add the webservice to store their email ids (I use a GitHub private repo)


7. Add

   eml-block

   in the survey flow again

Qualtrics.SurveyEngine.addOnload(function()
{
    var x = "${e://Field/eml-asked}";
    if(x=="true"){  
        //Change the query selector based on your question
        document.querySelector("#QR\\\\~"+this.questionId).value="eml@removed.auto";
        this.getQuestionContainer().hide();
        this.clickNextButton();
    }
    Qualtrics.SurveyEngine.setEmbeddedData("eml-asked", "true");


});
Here's why it works. When the same question block is used more than once in a survey, Qualtrics only stores the last value of the answer. Here, the email id is captured once, then stored somewhere else. The second time the question is in the block, the email id has been removed and hence that value is stored in the answers.

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