Tracking emails and partial responses

Hello,

This is my problem. 
I would like to collect partial data from my satisfaction survey and find out the email addresses of the respondents. I have therefore created two typeforms. I redirect the first one to the second. 

I can find out the email address of the person who is answering the survey in the first typeform but not in the second. 

How can I do this? 

Thank you for your help in advance