@januwine @Liz - if you are sending it out of a CRM system, most of them will track email open and link click. That would at least give you a way to track back on how many folks (including who) opened the email and then clicked the link to the form.
That way if you send it to a population of 400 and 360 opened the email (per the CRM reporting) and of those 320 clicked the link to the form (per the CRM reporting) you would have an idea of how many folks have gone to the form.
Typeform will record the number of submissions of the form - hopefully in the example so far, 320 of them
you would need to manually reconcile your numbers from the reports.
What you could in the crm system is assign a tag to the people who open the email ie ‘survey_email_opened’ and again for those who clicked the link to the typeform ie ‘survey_link_clicked’
at this point you still have no clue if they completed the form or not … just that they went there.. (ok if you know who opened and clicked the link and the number of link clicks = the number of typeform submissions you know who responded… )
you could then have the crm system send an email to all the folks in the target population who do not have both of the defined tags ie they may not have opened the email, they may have opened the email but not clicked the link - i would send the email out with the addresses on the bcc line so that know one knows that this is a limited distribution.
and track it again..
you can continue this until you have 400 opens, 400 clicks and 400 responses. the responses are anonymous but you know the population has responded.
just my thoughts when i need another coffee..
des