GDPR compliant review reminder Emails - checkbox to collect consent

In order to comply with European GDPR, you have to collect customer consent *before* you send any review reminder Emails.

Note that it's not enough when customers have agreed to receive e.g. general promotional newsletters.

So for now I have deactivated Email reminders, otherwise I'd be violating GDPR.

However, I think there is a relatively easy fix for this, which I'd like to suggest here:
Just place a checkbox inside the checkout process ("Yes, I want to receive review reminder Emails").
If the customer doesn't agree, set their email address onto the blacklist.
Note that consent requires a positive opt-in, so don’t use pre-ticked boxes (at least for EU customers).

Kristina