diff --git a/src/main/java/org/olat/commons/memberlist/ui/MembersMailController.java b/src/main/java/org/olat/commons/memberlist/ui/MembersMailController.java
index b82f12ecd25aeda97b76b6c899e0f00d96348c98..cc5887ad53d8af37c57bde5f3c8fea38f78aef42 100644
--- a/src/main/java/org/olat/commons/memberlist/ui/MembersMailController.java
+++ b/src/main/java/org/olat/commons/memberlist/ui/MembersMailController.java
@@ -309,7 +309,7 @@ public class MembersMailController extends FormBasicController {
 			} else if (individualEl != null && !individualEl.isAtLeastSelected(1)) {
 				individualEl.setErrorKey("at.least.one.recipient", null);
 			} else if (externalEl != null && !externalEl.isAtLeastSelected(1)) {
-				individualEl.setErrorKey("at.least.one.recipient", null);
+				externalEl.setErrorKey("at.least.one.recipient", null);
 			}
 		}