Access to the requested URL was blocked

While trying to access the URL:
/glaswelten?mailto=berger%2540holz-rentsch.de&subject=Beratungsgespr%25C3%25A4ch%2520f%25C3%25BCr%2520Glaswelten%2520vereinbar
The content is blocked for the following condition:
waf
Additional information:
Inbound Anomaly Score Exceeded (Total Score: 6, SQLi=, XSS=): Last Matched Message: Multiple URL Encoding Detected
This incident was logged with the following log identifier:
ZgX7IkLEAbdyQW4mQx6@awAAABk
Your cache administrator is:
astaroadmin@dokumenta.de