Experimental: send user unknown

FAQ.md

@@ -2863,6 +2863,10 @@ Please see [this FAQ](#user-content-faq163) for details.
 
 Since this is an experimental feature, my advice is to start with just one folder.
 
+*Send user unknown (version 1.1477+)*
+
+Send a [Delivery Status Notification](https://tools.ietf.org/html/rfc3464) *User unknown* via the answer menu.
+
 <br />
 
 <a name="faq126"></a>

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -3349,7 +3349,8 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
 
         private void onReceipt(TupleMessageEx message) {
             Intent reply = new Intent(context, ActivityCompose.class)
-                    .putExtra("action", "receipt")
+                    .putExtra("action", "dsn")
+                    .putExtra("dsn", EntityMessage.DSN_RECEIPT)
                     .putExtra("reference", message.id);
             context.startActivity(reply);
         }

app/src/main/java/eu/faircode/email/ApplicationEx.java

@@ -407,6 +407,9 @@ public class ApplicationEx extends Application
         } else if (version < 1463) {
             if (!prefs.contains("autoscroll"))
                 editor.putBoolean("autoscroll", true);
+        } else if (version < 1477) {
+            if (!BuildConfig.DEBUG)
+                editor.remove("experiments");
         }
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && !BuildConfig.DEBUG)

app/src/main/java/eu/faircode/email/EntityMessage.java

@@ -104,6 +104,7 @@ public class EntityMessage implements Serializable {
 
     static final Integer DSN_NONE = 0;
     static final Integer DSN_RECEIPT = 1;
+    static final Integer DSN_USER_UNKNOWN = 2;
 
     static final Long SWIPE_ACTION_ASK = -1L;
     static final Long SWIPE_ACTION_SEEN = -2L;

app/src/main/java/eu/faircode/email/FragmentCompose.java

@@ -1184,6 +1184,7 @@ public class FragmentCompose extends FragmentBase {
                 args.putLong("account", a.getLong("account", -1));
                 args.putLong("identity", a.getLong("identity", -1));
                 args.putLong("reference", a.getLong("reference", -1));
+                args.putInt("dsn", a.getInt("dsn", -1));
                 args.putSerializable("ics", a.getSerializable("ics"));
                 args.putString("status", a.getString("status"));
                 args.putBoolean("raw", a.getBoolean("raw", false));
@@ -3388,6 +3389,7 @@ public class FragmentCompose extends FragmentBase {
             String action = args.getString("action");
             long id = args.getLong("id", -1);
             long reference = args.getLong("reference", -1);
+            int dsn = args.getInt("dsn", EntityMessage.DSN_RECEIPT);
             File ics = (File) args.getSerializable("ics");
             String status = args.getString("status");
             long answer = args.getLong("answer", -1);
@@ -3609,7 +3611,7 @@ public class FragmentCompose extends FragmentBase {
                         // References
                         if ("reply".equals(action) || "reply_all".equals(action) ||
                                 "list".equals(action) ||
-                                "receipt".equals(action) ||
+                                "dsn".equals(action) ||
                                 "participation".equals(action)) {
                             data.draft.references = (ref.references == null ? "" : ref.references + " ") + ref.msgid;
                             data.draft.inreplyto = ref.msgid;
@@ -3617,7 +3619,7 @@ public class FragmentCompose extends FragmentBase {
 
                             if ("list".equals(action) && ref.list_post != null)
                                 data.draft.to = ref.list_post;
-                            else if ("receipt".equals(action) && ref.receipt_to != null)
+                            else if ("dsn".equals(action) && ref.receipt_to != null)
                                 data.draft.to = ref.receipt_to;
                             else {
                                 // Prevent replying to self
@@ -3667,8 +3669,8 @@ public class FragmentCompose extends FragmentBase {
 
                             if ("reply_all".equals(action))
                                 data.draft.cc = ref.getAllRecipients(data.identities, ref.account);
-                            else if ("receipt".equals(action)) {
+                            else if ("dsn".equals(action)) {
-                                data.draft.dsn = EntityMessage.DSN_RECEIPT;
+                                data.draft.dsn = dsn;
                                 data.draft.receipt_request = false;
                             }
 
@@ -3727,10 +3729,17 @@ public class FragmentCompose extends FragmentBase {
                             }
                         } else if ("list".equals(action)) {
                             data.draft.subject = ref.subject;
-                        } else if ("receipt".equals(action)) {
+                        } else if ("dsn".equals(action)) {
-                            data.draft.subject = context.getString(R.string.title_receipt_subject, subject);
+                            if (EntityMessage.DSN_USER_UNKNOWN.equals(dsn))
+                                data.draft.subject = context.getString(R.string.title_user_unknown_subject);
+                            else
+                                data.draft.subject = context.getString(R.string.title_receipt_subject, subject);
 
-                            String[] texts = Helper.getStrings(context, ref.language, R.string.title_receipt_text);
+                            String[] texts;
+                            if (EntityMessage.DSN_USER_UNKNOWN.equals(dsn))
+                                texts = new String[]{context.getString(R.string.title_user_unknown_text)};
+                            else
+                                texts = Helper.getStrings(context, ref.language, R.string.title_receipt_text);
                             for (int i = 0; i < texts.length; i++) {
                                 if (i > 0)
                                     document.body()
@@ -3782,7 +3791,7 @@ public class FragmentCompose extends FragmentBase {
                         if (ref.content &&
                                 !"editasnew".equals(action) &&
                                 !("list".equals(action) && TextUtils.isEmpty(s)) &&
-                                !"receipt".equals(action)) {
+                                !"dsn".equals(action)) {
                             // Reply/forward
                             Element reply = document.createElement("div");
                             reply.attr("fairemail", "reference");

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -2410,6 +2410,10 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                 if (data.identities == null)
                     data.identities = new ArrayList<>();
 
+                final Context context = getContext();
+                if (context == null)
+                    return;
+
                 final Address[] to =
                         message.replySelf(data.identities, message.account)
                                 ? message.to
@@ -2419,13 +2423,17 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
 
                 int answers = args.getInt("answers");
 
-                PopupMenuLifecycle popupMenu = new PopupMenuLifecycle(getContext(), getViewLifecycleOwner(), anchor);
+                SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+                boolean experiments = prefs.getBoolean("experiments", false);
+
+                PopupMenuLifecycle popupMenu = new PopupMenuLifecycle(context, getViewLifecycleOwner(), anchor);
                 popupMenu.inflate(R.menu.popup_reply);
                 popupMenu.getMenu().findItem(R.id.menu_reply_to_all).setVisible(recipients.length > 0);
                 popupMenu.getMenu().findItem(R.id.menu_reply_list).setVisible(message.list_post != null);
                 popupMenu.getMenu().findItem(R.id.menu_reply_receipt).setVisible(message.receipt_to != null);
+                popupMenu.getMenu().findItem(R.id.menu_reply_user_unknown).setVisible(experiments);
                 popupMenu.getMenu().findItem(R.id.menu_new_message).setVisible(to != null && to.length > 0);
-                popupMenu.getMenu().findItem(R.id.menu_reply_answer).setVisible(answers != 0 || !ActivityBilling.isPro(getContext()));
+                popupMenu.getMenu().findItem(R.id.menu_reply_answer).setVisible(answers != 0 || !ActivityBilling.isPro(context));
 
                 popupMenu.getMenu().findItem(R.id.menu_reply_to_sender).setEnabled(message.content);
                 popupMenu.getMenu().findItem(R.id.menu_reply_to_all).setEnabled(message.content);
@@ -2446,7 +2454,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                     @Override
                     public boolean onMenuItemClick(MenuItem target) {
                         if (target.getGroupId() == 1) {
-                            startActivity(new Intent(getContext(), ActivityCompose.class)
+                            startActivity(new Intent(context, ActivityCompose.class)
                                     .putExtra("action", "reply")
                                     .putExtra("reference", message.id)
                                     .putExtra("answer", target.getIntent().getLongExtra("id", -1)));
@@ -2465,7 +2473,10 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                                 onMenuReply(message, "list", selected);
                                 return true;
                             case R.id.menu_reply_receipt:
-                                onMenuReply(message, "receipt");
+                                onMenuDsn(message, EntityMessage.DSN_RECEIPT);
+                                return true;
+                            case R.id.menu_reply_user_unknown:
+                                onMenuDsn(message, EntityMessage.DSN_USER_UNKNOWN);
                                 return true;
                             case R.id.menu_forward:
                                 onMenuReply(message, "forward");
@@ -2506,6 +2517,14 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
         startActivity(reply);
     }
 
+    private void onMenuDsn(TupleMessageEx message, int type) {
+        Intent reply = new Intent(getContext(), ActivityCompose.class)
+                .putExtra("action", "dsn")
+                .putExtra("reference", message.id)
+                .putExtra("dsn", type);
+        startActivity(reply);
+    }
+
     private void onMenuNew(TupleMessageEx message, Address[] to) {
         Intent reply = new Intent(getContext(), ActivityCompose.class)
                 .putExtra("action", "new")

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -573,6 +573,43 @@ public class MessageHelper {
             //headersPart.setDisposition(Part.INLINE);
             //report.addBodyPart(headersPart);
 
+            imessage.setContent(report);
+            return;
+        } else if (EntityMessage.DSN_USER_UNKNOWN.equals(message.dsn)) {
+            // https://tools.ietf.org/html/rfc3464
+            Multipart report = new MimeMultipart("report; report-type=delivery-status");
+
+            String html = Helper.readText(message.getFile(context));
+            String plainContent = HtmlHelper.getText(context, html);
+
+            BodyPart plainPart = new MimeBodyPart();
+            plainPart.setContent(plainContent, "text/plain; charset=" + Charset.defaultCharset().name());
+            report.addBodyPart(plainPart);
+
+            String from = null;
+            if (message.from != null && message.from.length > 0)
+                from = ((InternetAddress) message.from[0]).getAddress();
+
+            StringBuilder sb = new StringBuilder();
+            sb.append("Reporting-MTA: dns;").append("dummy.faircode.eu").append("\r\n");
+            sb.append("\r\n");
+
+            if (from != null)
+                sb.append("Final-Recipient: rfc822;").append(from).append("\r\n");
+
+            sb.append("Action: failed").append("\r\n");
+            sb.append("Status: 5.1.1").append("\r\n"); // https://tools.ietf.org/html/rfc3463
+            sb.append("Diagnostic-Code: smtp; 550 user unknown").append("\r\n");
+
+            MailDateFormat mdf = new MailDateFormat();
+            mdf.setTimeZone(TimeZone.getTimeZone("UTC"));
+            sb.append("Last-Attempt-Date: ").append(mdf.format(message.received)).append("\r\n");
+
+            BodyPart dnsPart = new MimeBodyPart();
+            dnsPart.setContent(sb.toString(), "message/delivery-status");
+            dnsPart.setDisposition(Part.INLINE);
+            report.addBodyPart(dnsPart);
+
             imessage.setContent(report);
             return;
         }

app/src/main/res/menu/popup_reply.xml

@@ -16,6 +16,10 @@
         android:id="@+id/menu_reply_receipt"
         android:title="@string/title_reply_receipt" />
 
+    <item
+        android:id="@+id/menu_reply_user_unknown"
+        android:title="@string/title_reply_user_unknown" />
+
     <item
         android:id="@+id/menu_forward"
         android:title="@string/title_forward" />

app/src/main/res/values/strings.xml

@@ -887,11 +887,15 @@
     <string name="title_reply_to_all">Reply to all</string>
     <string name="title_reply_list">Reply to list</string>
     <string name="title_reply_receipt">Send read receipt</string>
+    <string name="title_reply_user_unknown" translatable="false">Send user unknown</string>
     <string name="title_reply_template">Reply with template</string>
     <string name="title_move_undo">Moving to %1$s (%2$d)</string>
     <string name="title_open_with">Open with</string>
     <string name="title_authentication_failed">%1$s authentication failed</string>
 
+    <string name="title_user_unknown_subject" translatable="false">Delivery Status Notification (Failure)</string>
+    <string name="title_user_unknown_text" translatable="false">Your message wasn\'t delivered because the address couldn\'t be found.</string>
+
     <string name="title_receipt_subject">Read receipt: %1$s</string>
     <string name="title_receipt_text">This read receipt only acknowledges that the message was displayed. There is no guarantee that the recipient has read the message contents.</string>