The double opt-in process (or DOI for short) is an explicit consent procedure in which the end consumer must explicitly confirm advertising contact by email. Without this procedure, you run the risk of being sent a reminder with a payment obligation.
Unsolicited emails are considered an invasion of privacy and regarded as spam. For this reason, the double opt-in process is mandatory for Quentn. This way, we guarantee that only those who have registered for emails receive them.