diff --git a/nachrichten-manager-server/src/test/java/de/ozgcloud/nachrichten/postfach/OsiPostfachServiceITCase.java b/nachrichten-manager-server/src/test/java/de/ozgcloud/nachrichten/postfach/OsiPostfachServiceITCase.java
new file mode 100644
index 0000000000000000000000000000000000000000..55bf5fd61e145251a134e8596aa10a657c996bdc
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+++ b/nachrichten-manager-server/src/test/java/de/ozgcloud/nachrichten/postfach/OsiPostfachServiceITCase.java
@@ -0,0 +1,94 @@
+package de.ozgcloud.nachrichten.postfach;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.context.event.EventListener;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+import org.springframework.test.context.TestPropertySource;
+import org.springframework.web.client.RestTemplate;
+
+import de.ozgcloud.common.test.ITCase;
+import de.ozgcloud.nachrichten.attributes.ClientAttributeService;
+import de.ozgcloud.nachrichten.email.EmailGrpcService;
+import de.ozgcloud.nachrichten.postfach.osi.MessageAttachmentService;
+import lombok.SneakyThrows;
+
+@ITCase
+@TestPropertySource(properties = {
+		"ozgcloud.osi.postfach.proxyapi.key=key",
+		"ozgcloud.osi.postfach.proxyapi.realm=realm",
+		"ozgcloud.osi.postfach.proxyapi.url=url",
+})
+class OsiPostfachServiceITCase {
+
+	@Autowired
+	private PostfachService postfachService;
+
+	@MockBean
+	private ClientAttributeService clientAttributeRemoteService;
+
+	@MockBean
+	private MessageAttachmentService messageAttachmentService;
+
+	@MockBean
+	private EmailGrpcService emailGrpcService;
+
+	@MockBean
+	private RestTemplate restTemplate;
+
+	@Autowired
+	private SentEventTestListener sentEventTestListener;
+
+	@BeforeEach
+	void mock() {
+		sentEventTestListener.reset();
+	}
+
+	@DisplayName("should call osi postfach send")
+	@Test
+	@SneakyThrows
+	void shouldCallOsiPostfachSend() {
+		var osiNachricht = PostfachNachrichtTestFactory.createBuilder()
+				.postfachAddress(PostfachAddressTestFactory.createBuilder()
+						.serviceKontoType("OSI")
+						.build()
+				)
+				.build();
+		var commandId = "aaaaa";
+		when(restTemplate.exchange(eq("url"), eq(HttpMethod.POST), any(), Mockito.<Class<String>>any())).thenReturn(ResponseEntity.ok("true"));
+
+
+		postfachService.sendMail(commandId, "userId", osiNachricht);
+
+		assertThat(sentEventTestListener.events)
+				.extracting(PostfachMailSentEvent::getSource)
+				.containsExactly(commandId);
+	}
+
+	@Component
+	static class SentEventTestListener {
+		final List<PostfachMailSentEvent> events = new ArrayList<>();
+
+		@EventListener
+		void onEvent(PostfachMailSentEvent event) {
+			events.add(event);
+		}
+
+		void reset() {
+			events.clear();
+		}
+	}
+
+}