Hi @tobias_wildling_shoes,
Welcome to the Community Forum! Very exciting to our Forum extend to Germany!
Yes, Zendesk Agents have the ability to add a tag in Zendesk that would mark the customers you either want or don’t want to receive a message from you. This Zendesk tag would come into Klaviyo as a profile property which you can then add as a trigger filter for your flow. I’d recommend checking out how to Use Properties to Filter Flows in this Help Center Article so you can customize who receives feedback survey emails from you and exclude the customers who have the Zendesk tag attached to them.
Additionally, to further control who receives the email and who doesn’t, you can turn your feedback email from Live > Manual. Updating the Sending Status to Manual means that recipients will be queued for this message, but no emails or SMS messages will be sent automatically. Instead, messages will be marked for review. You can manually review recipients and choose to send or discard the emails.
Ich wünsche ihnen einen wunderbaren Tag,
-Taylor