When you send your quiz online form our sending platform ("Publish" unit, "Email" tab), you can send a reminder to the people who have not started answering to the questionnaire.
By activating that option, those who are in the process of filling in or those who have completed the questionnaire among your contact list will not receive your email. This only works if your contacts have already received a first invitation email for the relevant questionaire. Therefore, Eval&GO will automatically send them their personal and unique link. There will be no risk of duplicates among your respondents.