[FIX] DSNBounce should add Auto-Submitted: auto-replied header (#2717)

Author: chibenwa

server/mailet/mailets/src/main/java/org/apache/james/transport/mailets/DSNBounce.java

@@ -20,6 +20,8 @@
 package org.apache.james.transport.mailets;
 
 import static org.apache.james.transport.mailets.remote.delivery.Bouncer.DELIVERY_ERROR;
+import static org.apache.mailet.base.AutomaticallySentMailDetector.AUTO_REPLIED_VALUE;
+import static org.apache.mailet.base.AutomaticallySentMailDetector.AUTO_SUBMITTED_HEADER;
 
 import java.net.InetAddress;
 import java.net.UnknownHostException;
@@ -395,6 +397,7 @@ private MimeMessage createBounceMessage(Mail originalMail) throws MessagingExcep
         MimeMessage newMessage = new MimeMessage(Session.getDefaultInstance(System.getProperties(), null));
         newMessage.setContent(multipart);
         newMessage.setHeader(RFC2822Headers.CONTENT_TYPE, multipart.getContentType());
+        newMessage.setHeader(AUTO_SUBMITTED_HEADER, AUTO_REPLIED_VALUE);
         return newMessage;
     }
 

server/mailet/mailets/src/test/java/org/apache/james/transport/mailets/DSNBounceTest.java

@@ -1463,4 +1463,37 @@ void deliveryErrorShouldBeAdded() throws Exception {
         assertThat(MimeMessageUtil.asString(sentMessage))
             .contains("Error message:\nThis is what happen...");
     }
+
+    @Test
+    void shouldAddAutoSubmittedHeader() throws Exception {
+        FakeMailetConfig mailetConfig = FakeMailetConfig.builder()
+            .mailetName(MAILET_NAME)
+            .mailetContext(fakeMailContext)
+            .setProperty("defaultStatus", "4.0.0")
+            .build();
+        dsnBounce.init(mailetConfig);
+
+        MailAddress senderMailAddress = new MailAddress("[email protected]");
+        FakeMail mail = FakeMail.builder()
+            .name(MAILET_NAME)
+            .sender(senderMailAddress)
+            .mimeMessage(MimeMessageBuilder.mimeMessageBuilder()
+                .setText("My content"))
+            .recipient("[email protected]")
+            .lastUpdated(Date.from(Instant.parse("2016-09-08T14:25:52.000Z")))
+            .remoteAddr("remoteHost")
+            .attribute(new Attribute(AttributeName.of("delivery-error"), AttributeValue.of("This is what happen...")))
+            .build();
+        mail.setDsnParameters(DsnParameters.builder().envId(DsnParameters.EnvId.of("xyz")).build().get());
+
+        dsnBounce.service(mail);
+
+        List<SentMail> sentMails = fakeMailContext.getSentMails();
+        assertThat(sentMails).hasSize(1);
+        SentMail sentMail = sentMails.get(0);
+        MimeMessage sentMessage = sentMail.getMsg();
+
+        assertThat(MimeMessageUtil.asString(sentMessage))
+            .contains("Auto-Submitted: auto-replied");
+    }
 }