diff --git a/src/test/java/de/ozgcloud/xta/client/XtaSchemaValidationITCase.java b/src/test/java/de/ozgcloud/xta/client/XtaSchemaValidationITCase.java
index 542c12c9e3d3d6460f3af92777c765774a747cdc..3a7fa5c380ddd9cfe74e15d196c1d5642d06f99c 100644
--- a/src/test/java/de/ozgcloud/xta/client/XtaSchemaValidationITCase.java
+++ b/src/test/java/de/ozgcloud/xta/client/XtaSchemaValidationITCase.java
@@ -80,8 +80,8 @@ class XtaSchemaValidationITCase {
 	void shouldThrowUnmarshallExceptionOnBadResponse() {
 		wireMockServer.stubFor(post(XTA_MOCK_SERVER_URL_PATH + "msgBoxPort.svc")
 				.willReturn(
-						XtaMockServerResponseTestFactory.createGetMessageResponse(
-								"2f45a9e9-ed40-4e14-a082-de0d063e56e7_Geschaeftsgang.Geschaeftsgang.0201.zip")));
+						XtaMockServerResponseTestFactory.createConstantGetMessageResponse(
+								"84d0edd7-709b-4a7b-9aac-b3ee82041ef0_Geschaeftsgang.Geschaeftsgang.0201.zip")));
 
 		var message = xtaService.getMessage("urn:de:xta:messageid:dataport_xta_210:db6ad282-c510-4154-a167-daaa8b9f345a", XtaIdentifier.builder()
 				.value("afmsh:ozg-cloud-stage-Utopia")
diff --git a/src/test/java/de/ozgcloud/xta/client/factory/XtaMockServerResponseTestFactory.java b/src/test/java/de/ozgcloud/xta/client/factory/XtaMockServerResponseTestFactory.java
index 25c79eb22143d4946e1fb6dbb163a104a5e13618..fbab5530905cf76ae743df3324784424ea555cf4 100644
--- a/src/test/java/de/ozgcloud/xta/client/factory/XtaMockServerResponseTestFactory.java
+++ b/src/test/java/de/ozgcloud/xta/client/factory/XtaMockServerResponseTestFactory.java
@@ -107,6 +107,31 @@ public class XtaMockServerResponseTestFactory {
 				.withHeader("Content-Type", MULTIPART_RELATED_CONTENT_TYPE)
 				.withBody(body);
 	}
+	public static ResponseDefinitionBuilder createConstantGetMessageResponse(String xtaAttachmentFileName) {
+
+		var envelopeXMLString = TestUtils.loadTextFile("mock-responses/getMessage/stage-example/example2/example.xml");
+
+		var body = combineParts(
+				createPart(
+						ENVELOPE_HEADERS,
+						envelopeXMLString
+				),
+				createPart(
+						Map.of(
+								"Content-ID", "<http://tempuri.org/1/638791906228054916>",
+								"Content-Transfer-Encoding", "base64",
+								"Content-Type", "application/octet-stream"
+						),
+						loadFileAsBase64(
+								getAttachmentFilePath(xtaAttachmentFileName)
+						)
+				)
+		);
+
+		return ok()
+				.withHeader("Content-Type", MULTIPART_RELATED_CONTENT_TYPE)
+				.withBody(body);
+	}
 
 	private static String createMessageMetadataXml(String xtaAttachmentFileName) {
 		return TestUtils.loadTextFile(
diff --git a/src/test/resources/mock-responses/getMessage/stage-example/2f45a9e9-ed40-4e14-a082-de0d063e56e7_Geschaeftsgang.Geschaeftsgang.0201.zip b/src/test/resources/mock-responses/getMessage/stage-example/84d0edd7-709b-4a7b-9aac-b3ee82041ef0_Geschaeftsgang.Geschaeftsgang.0201.zip
similarity index 100%
rename from src/test/resources/mock-responses/getMessage/stage-example/2f45a9e9-ed40-4e14-a082-de0d063e56e7_Geschaeftsgang.Geschaeftsgang.0201.zip
rename to src/test/resources/mock-responses/getMessage/stage-example/84d0edd7-709b-4a7b-9aac-b3ee82041ef0_Geschaeftsgang.Geschaeftsgang.0201.zip
diff --git a/src/test/resources/mock-responses/getMessage/stage-example/example2/example.xml b/src/test/resources/mock-responses/getMessage/stage-example/example2/example.xml
index 73f9d6e53d25a650f48d1c0d5cddb9d8de610d1b..ad95df277c6d08741d63c2d9c793b495a017ebee 100644
--- a/src/test/resources/mock-responses/getMessage/stage-example/example2/example.xml
+++ b/src/test/resources/mock-responses/getMessage/stage-example/example2/example.xml
@@ -1,59 +1 @@
-<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope" xmlns:a="http://www.w3.org/2005/08/addressing">
-	<s:Header>
-		<a:Action s:mustUnderstand="1">http://www.osci.eu/ws/2008/05/transport/urn/messageTypes/MsgBoxFetchRequest
-		</a:Action>
-		<h:MsgBoxResponse MsgBoxRequestID="urn:de:xta:messageid:dataport_xta_210:0b2d4796-7f31-40c3-b834-7f7c66c042c9"
-				xmlns:h="http://www.osci.eu/ws/2008/05/transport" xmlns="http://www.osci.eu/ws/2008/05/transport"
-		>
-			<ItemsPending>0</ItemsPending>
-		</h:MsgBoxResponse>
-		<h:MessageMetaData xmlns:h="http://www.osci.eu/ws/2014/10/transport"
-				xmlns="http://www.osci.eu/ws/2014/10/transport">
-			<DeliveryAttributes>
-				<Origin>2025-04-02T10:49:30.324</Origin>
-				<Delivery>2025-04-02T10:49:32.893</Delivery>
-			</DeliveryAttributes>
-			<Originators>
-				<Author>
-					<Identifier type="xoev">afmsh:WebMethod_Online-Dienste</Identifier>
-				</Author>
-			</Originators>
-			<Destinations>
-				<Reader>
-					<Identifier type="xoev">afmsh:ozg-cloud-stage-Utopia</Identifier>
-				</Reader>
-			</Destinations>
-			<MsgIdentification>
-				<MessageID xmlns="http://www.w3.org/2005/08/addressing">
-					urn:de:xta:messageid:dataport_xta_210:0b2d4796-7f31-40c3-b834-7f7c66c042c9
-				</MessageID>
-			</MsgIdentification>
-			<Qualifier>
-				<Service>urn:xdomea:AFM</Service>
-				<BusinessScenario>
-					<Defined listURI="urn:de:dataport:codeliste:business.scenario" listVersionID="1">
-						<code xmlns="">AFM_DATA</code>
-					</Defined>
-				</BusinessScenario>
-				<MessageType listURI="urn:de:payloadSchema:elementName" listVersionID="1.0"
-						payloadSchema="http://www.xdomea.de/V2.0.1">
-					<code xmlns="">Geschaeftsgang.Geschaeftsgang.0201</code>
-				</MessageType>
-			</Qualifier>
-			<MsgSize>57890</MsgSize>
-		</h:MessageMetaData>
-		<a:RelatesTo>urn:uuid:0cb6ed55-8ac9-492a-9e76-6235e41729ea</a:RelatesTo>
-	</s:Header>
-	<s:Body>
-		<GenericContentContainer xmlns="http://xoev.de/transport/xta/211">
-			<ContentContainer>
-				<Message contentType="application/zip"
-						filename="1088975e-5892-474e-a0e9-d3cef8ee61db_Geschaeftsgang.Geschaeftsgang.0201.zip"
-						id="1088975e-5892-474e-a0e9-d3cef8ee61db" size="57890">
-					<xop:Include href="cid:http://tempuri.org/1/638791906226975019"
-							xmlns:xop="http://www.w3.org/2004/08/xop/include" />
-				</Message>
-			</ContentContainer>
-		</GenericContentContainer>
-	</s:Body>
-</s:Envelope>
\ No newline at end of file
+<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope" xmlns:a="http://www.w3.org/2005/08/addressing"><s:Header><a:Action s:mustUnderstand="1">http://www.osci.eu/ws/2008/05/transport/urn/messageTypes/MsgBoxFetchRequest</a:Action><h:MsgBoxResponse MsgBoxRequestID="urn:de:xta:messageid:dataport_xta_210:b32f749e-8188-49a9-add4-3e0f3c309f78" xmlns:h="http://www.osci.eu/ws/2008/05/transport" xmlns="http://www.osci.eu/ws/2008/05/transport" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><ItemsPending>0</ItemsPending></h:MsgBoxResponse><h:MessageMetaData xmlns:h="http://www.osci.eu/ws/2014/10/transport" xmlns="http://www.osci.eu/ws/2014/10/transport"><DeliveryAttributes><Origin>2025-04-02T10:41:30.488</Origin><Delivery>2025-04-02T10:41:33.17</Delivery></DeliveryAttributes><Originators><Author><Identifier type="xoev">afmsh:WebMethod_Online-Dienste</Identifier></Author></Originators><Destinations><Reader><Identifier type="xoev">afmsh:ozg-cloud-stage-Utopia</Identifier></Reader></Destinations><MsgIdentification><MessageID xmlns="http://www.w3.org/2005/08/addressing">urn:de:xta:messageid:dataport_xta_210:b32f749e-8188-49a9-add4-3e0f3c309f78</MessageID></MsgIdentification><Qualifier><Service>urn:xdomea:AFM</Service><BusinessScenario><Defined listURI="urn:de:dataport:codeliste:business.scenario" listVersionID="1"><code xmlns="">AFM_DATA</code></Defined></BusinessScenario><MessageType listURI="urn:de:payloadSchema:elementName" listVersionID="1.0" payloadSchema="http://www.xdomea.de/V2.0.1"><code xmlns="">Geschaeftsgang.Geschaeftsgang.0201</code></MessageType></Qualifier><MsgSize>57828</MsgSize></h:MessageMetaData><a:RelatesTo>urn:uuid:f3942209-ef9c-4371-9a12-df4fc4b846a8</a:RelatesTo></s:Header><s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><GenericContentContainer xmlns="http://xoev.de/transport/xta/211"><ContentContainer><Message contentType="application/zip" filename="84d0edd7-709b-4a7b-9aac-b3ee82041ef0_Geschaeftsgang.Geschaeftsgang.0201.zip" id="84d0edd7-709b-4a7b-9aac-b3ee82041ef0" size="57828"><xop:Include href="cid:http://tempuri.org/1/638791906228054916" xmlns:xop="http://www.w3.org/2004/08/xop/include"/></Message></ContentContainer></GenericContentContainer></s:Body></s:Envelope>
\ No newline at end of file