How can I disable that wallee sends any emails to my customers?

Per default we send the emails to your customers. However, you can easily disable and suspend this for all emails sent by the platform:

1. Go to Emails > Configuration
2. Click on Suspend Email Sending

You can anytime enable the email sending. If you want to simply stop certain emails from being sent you have the option on the configuration page to deactivate only certain emails. In the screenshot below only the sending of the authorization email is disabled. All other emails will be sent when triggered.