diff --git a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteService.java b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteService.java
index a3d3ccdbf31cf972eb11c14d4891a93ecfaafe5c..c03d4e681f51ff7a38fb4741ac21e92e187638e6 100644
--- a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteService.java
+++ b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteService.java
@@ -34,7 +34,7 @@ public class OsiPostfachRemoteService implements PostfachRemoteService {
 	public Stream<PostfachNachricht> getAllMessages() {
 		try {
 			return postfachApiFacadeService.receiveMessages();
-		}catch (RuntimeException e) {
+		} catch (RuntimeException e) {
 			throw new OsiPostfachException("Failed to get messages", e);
 		}
 	}
diff --git a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/ApiClientConfiguration.java b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/ApiClientConfiguration.java
index 82ea45f9be3c833242551186e6f7fea9e400c9c7..a0d414ec0f8b44661bc2a9dd1dda47983f17eb66 100644
--- a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/ApiClientConfiguration.java
+++ b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/ApiClientConfiguration.java
@@ -51,8 +51,7 @@ public class ApiClientConfiguration {
 	}
 
 	private RestClient restClient(ClientRegistrationRepository clientRegistrations) {
-		OAuth2ClientHttpRequestInterceptor requestInterceptor =
-				new OAuth2ClientHttpRequestInterceptor(authorizedClientManager(clientRegistrations));
+		var requestInterceptor = new OAuth2ClientHttpRequestInterceptor(authorizedClientManager(clientRegistrations));
 		requestInterceptor.setClientRegistrationIdResolver(request -> "osi2");
 
 		return defaultRestClientBuilder()
diff --git a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/Osi2PostfachProperties.java b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/Osi2PostfachProperties.java
index f5a3d44421b73db9566abbe773b7d2d54fc28b84..81ef4623dcd53c1d2ab13b03c5b233bd79de5386 100644
--- a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/Osi2PostfachProperties.java
+++ b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/config/Osi2PostfachProperties.java
@@ -17,7 +17,7 @@ import lombok.Setter;
 @RequiredArgsConstructor
 public class Osi2PostfachProperties {
 
-	public static final String PREFIX = "ozgcloud.osiv2-postfach";
+	public static final String PREFIX = "ozgcloud.osiv2";
 
 	private boolean enabled;
 
@@ -30,7 +30,7 @@ public class Osi2PostfachProperties {
 	@Configuration
 	@ConfigurationProperties(prefix = ApiConfiguration.PREFIX)
 	public static class ApiConfiguration {
-		static final String PREFIX = Osi2PostfachProperties.PREFIX + ".api";
+		public static final String PREFIX = Osi2PostfachProperties.PREFIX + ".api";
 
 		private String resource;
 		private String url;
@@ -47,7 +47,7 @@ public class Osi2PostfachProperties {
 	@Configuration
 	@ConfigurationProperties(prefix = ProxyConfiguration.PREFIX)
 	public static class ProxyConfiguration {
-		static final String PREFIX = Osi2PostfachProperties.PREFIX + ".http-proxy";
+		public static final String PREFIX = Osi2PostfachProperties.PREFIX + ".proxy";
 
 		private boolean enabled;
 
diff --git a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/RequestMapper.java b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2RequestMapper.java
similarity index 98%
rename from src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/RequestMapper.java
rename to src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2RequestMapper.java
index c9a42ae3fa9756dfe2ac34d20bfd73405f85a5fe..4b1482c4efeb283320bd9abace07dc89da77f52f 100644
--- a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/RequestMapper.java
+++ b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2RequestMapper.java
@@ -17,7 +17,7 @@ import de.ozgcloud.nachrichten.postfach.osiv2.gen.model.V1References;
 import de.ozgcloud.nachrichten.postfach.osiv2.gen.model.V1ReplyBehavior;
 
 @Mapper(unmappedTargetPolicy = ReportingPolicy.ERROR)
-public interface RequestMapper {
+public interface Osi2RequestMapper {
 
 	@Mapping(target = "sequencenumber", source = "vorgangId")
 	@Mapping(target = "body", source = "mailBody")
diff --git a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/ResponseMapper.java b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2ResponseMapper.java
similarity index 97%
rename from src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/ResponseMapper.java
rename to src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2ResponseMapper.java
index 84a1b80ce2f3ac508b39ce35bd9c52edc6f5ce4b..f5acb80a874aed8cf323aca797cbc5488f7846f5 100644
--- a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/ResponseMapper.java
+++ b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2ResponseMapper.java
@@ -1,7 +1,6 @@
 package de.ozgcloud.nachrichten.postfach.osiv2.transfer;
 
 import java.time.ZoneOffset;
-import java.time.format.DateTimeFormatter;
 
 import org.mapstruct.Mapper;
 import org.mapstruct.Mapping;
@@ -17,7 +16,7 @@ import lombok.Builder;
 import lombok.Getter;
 
 @Mapper(unmappedTargetPolicy = ReportingPolicy.ERROR, imports = ZoneOffset.class)
-public interface ResponseMapper {
+public interface Osi2ResponseMapper {
 
 	String POSTFACH_ADDRESS_VERSION = "2.0";
 	int POSTFACH_ADDRESS_TYPE = 2;
diff --git a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeService.java b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeService.java
index ed46e2754ff8ee868693d8f2415ccea958bccdad..d11c556369fb8c3a892d1be7c46476c0b7298ca6 100644
--- a/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeService.java
+++ b/src/main/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeService.java
@@ -1,5 +1,7 @@
 package de.ozgcloud.nachrichten.postfach.osiv2.transfer;
 
+import java.util.Collection;
+import java.util.Optional;
 import java.util.UUID;
 import java.util.stream.Stream;
 
@@ -20,27 +22,29 @@ import lombok.extern.log4j.Log4j2;
 public class PostfachApiFacadeService {
 
 	private final MessageExchangeApi messageExchangeApi;
-	private final RequestMapper requestMapper;
-	private final  ResponseMapper responseMapper;
+	private final Osi2RequestMapper osi2RequestMapper;
+	private final Osi2ResponseMapper osi2ResponseMapper;
 
 	private static final int MAX_NUMBER_RECEIVED_MESSAGES = 100;
 
 	public void sendMessage(PostfachNachricht nachricht) {
 		messageExchangeApi.sendMessage(
-				requestMapper.mapMailboxId(nachricht),
-				requestMapper.mapOutSendMessageRequestV2(nachricht)
+				osi2RequestMapper.mapMailboxId(nachricht),
+				osi2RequestMapper.mapOutSendMessageRequestV2(nachricht)
 		);
 	}
 
 	public Stream<PostfachNachricht> receiveMessages() {
 		var response = messageExchangeApi.receiveMessages(MAX_NUMBER_RECEIVED_MESSAGES, 0);
-		// TODO response.getMessages() is Nullable
-		return response.getMessages().stream().map(this::fetchMessageByGuid);
+		return Optional.ofNullable(response.getMessages())
+				.stream()
+				.flatMap(Collection::stream)
+				.map(this::fetchMessageByGuid);
 	}
 
 	PostfachNachricht fetchMessageByGuid(final MessageExchangeReceiveMessage message) {
 		var messageReply = messageExchangeApi.getMessage(message.getGuid());
-		return responseMapper.toPostfachNachricht(messageReply);
+		return osi2ResponseMapper.toPostfachNachricht(messageReply);
 	}
 
 	public void deleteMessage(final String messageId) {
diff --git a/src/main/resources/application-stage.yml b/src/main/resources/application-stage.yml
index 6892480bd6613072000a2bd939e6a72845bd109b..c2804acf5bd4bec3a1e037f7cf334c73b2905050 100644
--- a/src/main/resources/application-stage.yml
+++ b/src/main/resources/application-stage.yml
@@ -13,14 +13,14 @@ spring:
           osi2:
             token-uri: 'https://idp.serviceportal-stage.schleswig-holstein.de/webidp2/connect/token'
 ozgcloud:
-  osiv2-postfach:
+  osiv2:
     enabled: false
     api:
       resource: 'urn:dataport:osi:postfach:rz2:stage:sh'
       url: 'https://api-gateway-stage.dataport.de:443/api/osi_postfach/1.0.0'
       tenant: 'SH'
       name-identifier: 'ozgkopfstelle'
-    http-proxy:
+    proxy:
       enabled: true
       host: 127.0.0.1
       port: 3128
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 1de65de1ef648fa076aed0b384f63e957c88fba8..0acee01ecdbf9d81f5ce6d8d565300107d75c0e3 100644
--- a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceITCase.java
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceITCase.java
@@ -36,7 +36,7 @@ import lombok.SneakyThrows;
 @SpringBootTest(classes = TestApplication.class)
 @ActiveProfiles({ "stage", "itcase" })
 @TestPropertySource(properties = {
-		"ozgcloud.osiv2-postfach.http-proxy.enabled=false",
+		"ozgcloud.osiv2.proxy.enabled=false",
 })
 class OsiPostfachRemoteServiceITCase {
 
@@ -53,8 +53,8 @@ class OsiPostfachRemoteServiceITCase {
 		registry.add("spring.security.oauth2.client.provider.osi2.token-uri", OSI_MOCK_SERVER_EXTENSION::getAccessTokenUrl);
 		registry.add("spring.security.oauth2.client.registration.osi2.scope", () -> CLIENT_SCOPES);
 		registry.add("spring.security.oauth2.client.registration.osi2.client-id", () -> CLIENT_ID);
-		registry.add("ozgcloud.osiv2-postfach.api.url", OSI_MOCK_SERVER_EXTENSION::getPostfachFacadeUrl);
-		registry.add("ozgcloud.osiv2-postfach.api.resource", () -> RESOURCE_URN);
+		registry.add("ozgcloud.osiv2.api.url", OSI_MOCK_SERVER_EXTENSION::getPostfachFacadeUrl);
+		registry.add("ozgcloud.osiv2.api.resource", () -> RESOURCE_URN);
 	}
 
 	private WireMockServer postfachFacadeMockServer;
diff --git a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceRemoteITCase.java b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceRemoteITCase.java
index 29f64ecbcd8799c1c24331dfc0cf1cee4bcf177b..be0f329f70b0c21b27b6fadf053334f948b37c15 100644
--- a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceRemoteITCase.java
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceRemoteITCase.java
@@ -6,7 +6,6 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
@@ -46,11 +45,11 @@ public class OsiPostfachRemoteServiceRemoteITCase {
 				() -> System.getenv("SH_STAGE_CLIENT_SECRET")
 		);
 		registry.add(
-				"ozgcloud.osiv2-postfach.http-proxy.host",
+				"ozgcloud.osiv2.proxy.host",
 				() -> matchProxyRegex(System.getenv("HTTP_PROXY")).group(1)
 		);
 		registry.add(
-				"ozgcloud.osiv2-postfach.http-proxy.port",
+				"ozgcloud.osiv2.proxy.port",
 				() -> matchProxyRegex(System.getenv("HTTP_PROXY")).group(2)
 		);
 	}
@@ -63,7 +62,6 @@ public class OsiPostfachRemoteServiceRemoteITCase {
 		throw new IllegalArgumentException("Proxy host and port not found in '%s'".formatted(text));
 	}
 
-	@Disabled
 	@DisplayName("send message")
 	@Nested
 	class TestSendMessage {
@@ -90,7 +88,6 @@ public class OsiPostfachRemoteServiceRemoteITCase {
 		}
 	}
 
-	@Disabled
 	@DisplayName("delete message")
 	@Nested
 	class TestDeleteMessageById {
diff --git a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceTest.java b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceTest.java
index a00ab88ae8b7d18aa79a228c651d55ff472a8289..685c36f61dd8d1d44afc185da5bf94bf3eb4ee67 100644
--- a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceTest.java
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/OsiPostfachRemoteServiceTest.java
@@ -81,6 +81,7 @@ class OsiPostfachRemoteServiceTest {
 
 			verify(postfachApiFacadeService).deleteMessage(any());
 		}
+
 		@DisplayName("should throw osi postfach exception on runtime exception")
 		@Test
 		void shouldThrowOsiPostfachExceptionOnRuntimeException() {
diff --git a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/RequestMapperTest.java b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2RequestMapperTest.java
similarity index 97%
rename from src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/RequestMapperTest.java
rename to src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2RequestMapperTest.java
index 0e67c3c307449847d9e9e89e936f6812938ae98a..3abec1a5f53dd2c897230896e38a443eebd4ce4d 100644
--- a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/RequestMapperTest.java
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2RequestMapperTest.java
@@ -23,9 +23,9 @@ import de.ozgcloud.nachrichten.postfach.osiv2.gen.model.OutSendMessageRequestV2;
 import de.ozgcloud.nachrichten.postfach.osiv2.gen.model.V1EidasLevel;
 import de.ozgcloud.nachrichten.postfach.osiv2.gen.model.V1ReplyBehavior;
 
-class RequestMapperTest {
+class Osi2RequestMapperTest {
 
-	private final RequestMapper mapper = Mappers.getMapper(RequestMapper.class);
+	private final Osi2RequestMapper mapper = Mappers.getMapper(Osi2RequestMapper.class);
 
 	@DisplayName("map mailbox id")
 	@Nested
diff --git a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/ResponseMapperTest.java b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2ResponseMapperTest.java
similarity index 96%
rename from src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/ResponseMapperTest.java
rename to src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2ResponseMapperTest.java
index c45f08e8c51cdf0d80cc3316672738c154559274..54586de660f6dacc6967dff94bdf70e6f3871d79 100644
--- a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/ResponseMapperTest.java
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/Osi2ResponseMapperTest.java
@@ -16,10 +16,10 @@ import de.ozgcloud.nachrichten.postfach.PostfachNachricht;
 import de.ozgcloud.nachrichten.postfach.osiv2.factory.V1ReplyMessageTestFactory;
 import de.ozgcloud.nachrichten.postfach.osiv2.gen.model.V1ReplyMessage;
 
-class ResponseMapperTest {
+class Osi2ResponseMapperTest {
 
 	@InjectMocks
-	private ResponseMapper mapper = Mappers.getMapper(ResponseMapper.class);
+	private Osi2ResponseMapper mapper = Mappers.getMapper(Osi2ResponseMapper.class);
 	private V1ReplyMessage message = V1ReplyMessageTestFactory.create();
 
 	@DisplayName("map V1ReplyMessage to PostfachNachricht")
diff --git a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeServiceTest.java b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeServiceTest.java
index 139ba192c9394ddb55d2657e094a2d9d15765866..c1abebba22f3e88935c0465e0bba99d6840a07e5 100644
--- a/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeServiceTest.java
+++ b/src/test/java/de/ozgcloud/nachrichten/postfach/osiv2/transfer/PostfachApiFacadeServiceTest.java
@@ -32,10 +32,10 @@ class PostfachApiFacadeServiceTest {
 	MessageExchangeApi messageExchangeApi;
 
 	@Mock
-	RequestMapper requestMapper;
+	Osi2RequestMapper osi2RequestMapper;
 
 	@Mock
-	ResponseMapper responseMapper;
+	Osi2ResponseMapper osi2ResponseMapper;
 
 	@DisplayName("send message")
 	@Nested
@@ -51,8 +51,8 @@ class PostfachApiFacadeServiceTest {
 
 		@BeforeEach
 		void mock() {
-			when(requestMapper.mapMailboxId(nachricht)).thenReturn(MAILBOX_ID);
-			when(requestMapper.mapOutSendMessageRequestV2(nachricht)).thenReturn(outSendMessageRequestV2);
+			when(osi2RequestMapper.mapMailboxId(nachricht)).thenReturn(MAILBOX_ID);
+			when(osi2RequestMapper.mapOutSendMessageRequestV2(nachricht)).thenReturn(outSendMessageRequestV2);
 			when(messageExchangeApi.sendMessage(any(), any())).thenReturn(messageExchangeSendMessageResponse);
 		}
 
@@ -107,17 +107,17 @@ class PostfachApiFacadeServiceTest {
 		@Test
 		void shouldCallResponseMapper(){
 			when(messageExchangeApi.getMessage(any())).thenReturn(replyMessage);
-			when(responseMapper.toPostfachNachricht(any())).thenReturn(PostfachNachrichtTestFactory.create());
+			when(osi2ResponseMapper.toPostfachNachricht(any())).thenReturn(PostfachNachrichtTestFactory.create());
 
 			postfachApiFacadeService.fetchMessageByGuid(receiveMessage);
 
-			verify(responseMapper).toPostfachNachricht(any());
+			verify(osi2ResponseMapper).toPostfachNachricht(any());
 		}
 
 		@Test
 		void shouldReturnPostfachNachricht(){
 			when(messageExchangeApi.getMessage(any())).thenReturn(replyMessage);
-			when(responseMapper.toPostfachNachricht(any())).thenReturn(PostfachNachrichtTestFactory.create());
+			when(osi2ResponseMapper.toPostfachNachricht(any())).thenReturn(PostfachNachrichtTestFactory.create());
 
 			var postfachNachricht = postfachApiFacadeService.fetchMessageByGuid(receiveMessage);
 
diff --git a/src/test/resources/application-itcase.yml b/src/test/resources/application-itcase.yml
index d8cacf79a13dd9feec526bea7afc6695e6f0b136..41e84786e9e76db63c2d6671a55ae56dddae6ea7 100644
--- a/src/test/resources/application-itcase.yml
+++ b/src/test/resources/application-itcase.yml
@@ -1,5 +1,5 @@
 ozgcloud:
-  osiv2-postfach:
+  osiv2:
     enabled: true
 logging:
   level: