We want to give our users the possibility to enrich or update their data through a form.
Unfortunately we found out that this happens without any confirmation from the user. So if someone knows the email adress of a client everybody can change/corrupt the data.
How can we make sure that the data update only takes place if/after the client confirms this via mail (like a DOI)?
Hi @davedee! Welcome to the AC Forum and thanks for posting your question here.
It seems that you are looking for an email confirmation after form submission, correct? This is precisely our double opt-in feature. You can view more details about the double opt-in here.. Hope this helps! 
Hi AC_Beatriz,
sorry, but thats what I´m not looking for 
I´m talking about the problem that it´s possible to damage data without confirmation.
Hi @davedee! Sorry for the confusion.
Anyone who submits the “Update my preferences” form will be able to update another contact’s information if they change the email address field. Unfortunately, we really can’t prevent this at the moment. But we understand how this would be necessary and helpful. We’d advise you to add this suggestion to our ideas.activecampaign.com.