diff --git a/README.md b/README.md
index b14b6e7..74b97b1 100644
--- a/README.md
+++ b/README.md
@@ -16,4 +16,5 @@ Information about how to configure email servers, services, etc.
 - https://stats.labs.apnic.net/dnssec/
 - https://stats.labs.apnic.net/dnssec
 - https://www.windowspro.de/news/microsoft-unterstuetzt-dane-dnssec-exchange-online/04980.html
+- https://testconnectivity.microsoft.com/tests/exo
 - https://testconnectivity.microsoft.com/tests/O365DaneValidation/input