diff --git a/spec/postfach-api-facade.yaml b/spec/postfach-api-facade.yaml
index f9730377d06df25d100193431405c9ab1ab5031a..0414d95e73a7a704396be50ed764b23684c96efe 100644
--- a/spec/postfach-api-facade.yaml
+++ b/spec/postfach-api-facade.yaml
@@ -1264,6 +1264,7 @@ paths:
                 detail: Der Dienst ist zurzeit nicht verfügbar.
   /MessageExchange/v1/Delete/{messageId}:
     delete:
+      operationId: deleteMessage
       tags:
       - MessageExchange
       summary: Löscht eine Nachricht.
diff --git a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceITCase.java b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceITCase.java
index 61602acc355d8389b6decf7279fd79167ec69ed0..2c07c7829eecea5369ae091c96b892161fe2095d 100644
--- a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceITCase.java
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceITCase.java
@@ -18,7 +18,6 @@ import java.util.UUID;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
 import org.mockserver.client.MockServerClient;
@@ -76,57 +75,46 @@ public class OsiPostfachRemoteServiceITCase {
 		postfachFacadeMockClient = OSI_MOCK_SERVER_EXTENSION.getPostfachFacadeMockClient();
 	}
 
-
-	@DisplayName("send message")
-	@Nested
-	class TestSendMessage {
-
-		@DisplayName("should send dummy request with jwt")
-		@Test
-		@SneakyThrows
-		void shouldSendDummyRequestWithJwt() {
-			postfachFacadeMockClient.upsert(
-					openAPIExpectation()
-							.withSpecUrlOrPayload(Files.readString(Path.of("spec", "postfach-api-facade.yaml")))
-							.withOperationsAndResponses(Map.of(
-									"SendMessage", "200"
-							))
-			);
-
-			osiPostfachRemoteService.sendMessage(postfachNachricht);
-
-			var requests = postfachFacadeMockClient.retrieveRecordedRequests(request());
-			assertThat(requests).hasSize(1);
-			var jwt = Jwt.parseAuthHeaderValue(
-					requests[0].getHeader("Authorization").getFirst()
-			);
-			assertThat(jwt.body().read("$.client_id", String.class)).isEqualTo(CLIENT_ID);
-			assertThat(jwt.body().read("$.aud", String.class)).isEqualTo(RESOURCE_URN);
-		}
-
+	@DisplayName("should send dummy request with jwt")
+	@Test
+	@SneakyThrows
+	void shouldSendDummyRequestWithJwt() {
+		postfachFacadeMockClient.upsert(
+				openAPIExpectation()
+						.withSpecUrlOrPayload(Files.readString(Path.of("spec", "postfach-api-facade.yaml")))
+						.withOperationsAndResponses(Map.of(
+								"SendMessage", "200"
+						))
+		);
+
+		osiPostfachRemoteService.sendMessage(postfachNachricht);
+
+		var requests = postfachFacadeMockClient.retrieveRecordedRequests(request());
+		assertThat(requests).hasSize(1);
+		var jwt = Jwt.parseAuthHeaderValue(
+				requests[0].getHeader("Authorization").getFirst()
+		);
+		assertThat(jwt.body().read("$.client_id", String.class)).isEqualTo(CLIENT_ID);
+		assertThat(jwt.body().read("$.aud", String.class)).isEqualTo(RESOURCE_URN);
 	}
 
-	@DisplayName("receive messages")
-	@Nested
-	class TestReceiveMessage {
-
 	ObjectMapper objectMapper = new ObjectMapper().registerModule(new JavaTimeModule());
 
-		@DisplayName("should receive one messages")
-		@Test
-		@SneakyThrows
-		void shouldReceiveMessages() {
-			var uuid = UUID.fromString("00000000-0000-0000-0000-000000000000");
+	@DisplayName("should receive one messages")
+	@Test
+	@SneakyThrows
+	void shouldReceiveMessages() {
+		var uuid = UUID.fromString("00000000-0000-0000-0000-000000000000");
 
-			createMessagesJson(uuid, null);
+		createMessagesJson(uuid, null);
 
-			createOneReplyMessageJson(uuid);
+		createOneReplyMessageJson(uuid);
 
-			var messageStream = osiPostfachRemoteService.getAllMessages();
+		var messageStream = osiPostfachRemoteService.getAllMessages();
 
-			var messageList = messageStream.toList();
-			assertThat(messageList).size().isEqualTo(1);
-		}
+		var messageList = messageStream.toList();
+		assertThat(messageList).size().isEqualTo(1);
+	}
 
 	@DisplayName("should receive two messages")
 	@Test
@@ -146,7 +134,7 @@ public class OsiPostfachRemoteServiceITCase {
 		assertThat(messageList).size().isEqualTo(2);
 	}
 
-	private void createMessagesJson(final UUID ... uuids) throws IOException {
+	private void createMessagesJson(final UUID... uuids) throws IOException {
 		var messagesList = Arrays.stream(uuids).filter(Objects::nonNull).map(uuid -> new MessageExchangeReceiveMessage().guid(uuid)).toList();
 
 		var messages = new MessageExchangeReceiveMessagesResponse().messages(messagesList);
@@ -176,25 +164,20 @@ public class OsiPostfachRemoteServiceITCase {
 
 		createMessagesCall("getMessage", messageJson);
 	}
-}
 
-	@DisplayName("delete messages")
-	@Nested
-	class TestDeleteMessage {
-
-		@DisplayName("should delete message")
-		@Test
-		@SneakyThrows
-		void shouldDeleteMessage(){
-			postfachFacadeMockClient.upsert(
-					openAPIExpectation()
-							.withSpecUrlOrPayload(Files.readString(Path.of("spec", "postfach-api-facade.yaml")))
-							.withOperationsAndResponses(Map.of(
-									"SendMessage", "200"
-							))
-			);
-
-			assertDoesNotThrow(() -> osiPostfachRemoteService.deleteMessage("00000000-0000-0000-0000-000000000000"));
-		}
+	@DisplayName("should delete message")
+	@Test
+	@SneakyThrows
+	void shouldDeleteMessage() {
+		postfachFacadeMockClient.upsert(
+				openAPIExpectation()
+						.withSpecUrlOrPayload(Files.readString(Path.of("spec", "postfach-api-facade.yaml")))
+						.withOperationsAndResponses(Map.of(
+								"deleteMessage", "200"
+						))
+		);
+
+		assertDoesNotThrow(() -> osiPostfachRemoteService.deleteMessage("00000000-0000-0000-0000-000000000000"));
 	}
+
 }