Hello,
Different options are available:
a.
- create SP useraccounts (menu: accounts/ userlist/ ....) including an emailaddress for every respondent;
- add the Repondents role to the user (menu edit user)
- add the survey to the user (menu edit user)
- Next the user logs in to the SP tool and answers/submits the survey (menu take survey)
- user details are all logged and all available including email
b.
- add the email code protection security add in to the survey (menu Security/ form security/ email code add in.)
- next invite respondents by sending an invitation mailing (menu campaigns/ mailing)
- when the survey is answered the email address is logged
- also the mailing status can be followed (menu campaigns/ mailing status)