Set resent headers correctly

FAQ.md

@@ -3407,7 +3407,7 @@ Remarks:
 * The original subject is sent as-is, unless it is being changed
 * The original message text will be sent as-is, unless text is being entered
 * The original attachments are sent as they are, unless attachments are being added or removed
-* Default CC and BCC addresses will be applied
+* Default CC and BCC addresses will not be applied
 * Read and delivery receipts will be requested when enabled, they could go to the original sender or to you
 * The email server might refused resent messages
 * DKIM, SPF and DMARC will likely fail, often causing resent messages to be considered as spam

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

@@ -281,75 +281,96 @@ public class MessageHelper {
 
         MailDateFormat mdf = new MailDateFormat();
         mdf.setTimeZone(hide_timezone ? TimeZone.getTimeZone("UTC") : TimeZone.getDefault());
-        String date = mdf.format(new Date(message.sent == null ? message.received : message.sent));
+        String ourDate = mdf.format(new Date(message.sent == null ? message.received : message.sent));
-        imessage.setHeader("Date", date);
 
-        Address us = null;
+        Address ourFrom = null;
-        if (message.from != null && message.from.length > 0) {
+        if (message.from != null && message.from.length > 0)
-            us = getFrom(message, identity);
+            ourFrom = getFrom(message, identity);
-            imessage.setFrom(us);
-        }
 
-        // Resend
+        if (message.headers == null) {
-        if (message.headers != null) {
+            imessage.setHeader("Date", ourDate);
+
+            // Addresses
+            if (ourFrom != null)
+                imessage.setFrom(ourFrom);
+
+            if (message.to != null && message.to.length > 0)
+                imessage.setRecipients(Message.RecipientType.TO, convertAddress(message.to, identity));
+
+            if (message.cc != null && message.cc.length > 0)
+                imessage.setRecipients(Message.RecipientType.CC, convertAddress(message.cc, identity));
+
+            if (message.bcc != null && message.bcc.length > 0)
+                imessage.setRecipients(Message.RecipientType.BCC, convertAddress(message.bcc, identity));
+        } else {
             // https://datatracker.ietf.org/doc/html/rfc2822#section-3.6.6
-            if (us != null)
-                imessage.addHeader("Resent-From", us.toString());
-
-            imessage.addHeader("Resent-Date", date);
-
             ByteArrayInputStream bis = new ByteArrayInputStream(message.headers.getBytes());
             List<Header> headers = Collections.list(new InternetHeaders(bis).getAllHeaders());
+
             for (Header header : headers) {
                 String name = header.getName();
                 String value = header.getValue();
-                if (name == null || value == null)
+                if (name == null || TextUtils.isEmpty(value))
                     continue;
 
                 switch (name.toLowerCase(Locale.ROOT)) {
-                    case "from":
-                        // Override default header
-                        imessage.setFrom(value);
-                        break;
                     case "date":
-                        // Override default header
                         imessage.setHeader("Date", value);
                         break;
-
+                    case "from":
+                        imessage.setFrom(value);
+                        break;
                     case "to":
-                        imessage.addHeader("Resent-To", value);
+                        imessage.setRecipients(Message.RecipientType.TO, InternetAddress.parse(value));
                         break;
                     case "cc":
-                        imessage.addHeader("Resent-Cc", value);
+                        imessage.setRecipients(Message.RecipientType.CC, InternetAddress.parse(value));
                         break;
                     case "bcc":
-                        imessage.addHeader("Resent-Bcc", value);
+                        imessage.setRecipients(Message.RecipientType.BCC, InternetAddress.parse(value));
+                        break;
+                    case "reply-to":
+                        imessage.setReplyTo(InternetAddress.parse(value));
                         break;
                     // Resent-Sender
                     // Resent-Message-ID
                 }
             }
 
+            // The "Resent-Date:" indicates the date and time at which the resent
+            //   message is dispatched by the resender of the message.
+            imessage.addHeader("Resent-Date", ourDate);
+
+            // a simple "Resent-From:" form which
+            //   contains the mailbox of the individual doing the resending
+            if (ourFrom != null)
+                imessage.addHeader("Resent-From", ourFrom.toString());
+
+            // The "Resent-To:", "Resent-Cc:", and "Resent-Bcc:" fields function
+            //   identically to the "To:", "Cc:", and "Bcc:" fields respectively,
+            //   except that they indicate the recipients of the resent message, not
+            //   the recipients of the original message.
+            if (message.to != null && message.to.length > 0)
+                imessage.addHeader("Resent-To", InternetAddress.toString(message.to));
+
+            if (message.cc != null && message.cc.length > 0)
+                imessage.addHeader("Resent-Cc", InternetAddress.toString(message.cc));
+
+            if (message.bcc != null && message.bcc.length > 0)
+                imessage.addHeader("Resent-Bcc", InternetAddress.toString(message.bcc));
+
+            // Each new set of resent fields is prepended to the message;
+            //   that is, the most recent set of resent fields appear earlier in the message.
             for (Header header : headers) {
                 String name = header.getName();
                 String value = header.getValue();
-                if (name == null || value == null)
+                if (name == null || TextUtils.isEmpty(value))
                     continue;
                 if (name.toLowerCase(Locale.ROOT).startsWith("resent-"))
                     imessage.addHeader(name, value);
             }
         }
 
-        // Addresses
-        if (message.to != null && message.to.length > 0)
-            imessage.setRecipients(Message.RecipientType.TO, convertAddress(message.to, identity));
-
-        if (message.cc != null && message.cc.length > 0)
-            imessage.setRecipients(Message.RecipientType.CC, convertAddress(message.cc, identity));
-
-        if (message.bcc != null && message.bcc.length > 0)
-            imessage.setRecipients(Message.RecipientType.BCC, convertAddress(message.bcc, identity));
-
         if (message.subject != null) {
             int maxlen = MAX_HEADER_LENGTH - "Subject: ".length();
             if (message.subject.length() > maxlen)
@@ -359,17 +380,19 @@ public class MessageHelper {
 
         // Send message
         if (identity != null) {
-            // Add reply to
+            if (message.headers == null) {
-            if (message.headers == null && identity.replyto != null)
+                // Add reply to
-                imessage.setReplyTo(convertAddress(InternetAddress.parse(identity.replyto), identity));
+                if (identity.replyto != null)
+                    imessage.setReplyTo(convertAddress(InternetAddress.parse(identity.replyto), identity));
 
-            // Add extra cc
+                // Add extra cc
-            if (identity.cc != null)
+                if (identity.cc != null)
-                addAddress(identity.cc, Message.RecipientType.CC, imessage, identity);
+                    addAddress(identity.cc, Message.RecipientType.CC, imessage, identity);
 
-            // Add extra bcc
+                // Add extra bcc
-            if (identity.bcc != null)
+                if (identity.bcc != null)
-                addAddress(identity.bcc, Message.RecipientType.BCC, imessage, identity);
+                    addAddress(identity.bcc, Message.RecipientType.BCC, imessage, identity);
+            }
 
             // Delivery/read request
             if (message.receipt_request != null && message.receipt_request) {

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

@@ -48,6 +48,8 @@ import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
@@ -681,9 +683,30 @@ public class ServiceSend extends ServiceBase implements SharedPreferences.OnShar
             if (ident.max_size == null)
                 max_size = iservice.getMaxSize();
 
-            Address[] to = imessage.getAllRecipients();
+            List<Address> recipients = new ArrayList<>();
+            if (message.headers == null) {
+                Address[] all = imessage.getAllRecipients();
+                if (all != null)
+                    recipients.addAll(Arrays.asList(all));
+            } else {
+                String to = imessage.getHeader("Resent-To", ",");
+                if (to != null)
+                    for (Address a : InternetAddress.parse(to))
+                        recipients.add(a);
+
+                String cc = imessage.getHeader("Resent-Cc", ",");
+                if (cc != null)
+                    for (Address a : InternetAddress.parse(cc))
+                        recipients.add(a);
+
+                String bcc = imessage.getHeader("Resent-Bcc", ",");
+                if (bcc != null)
+                    for (Address a : InternetAddress.parse(bcc))
+                        recipients.add(a);
+            }
+
             String via = "via " + ident.host + "/" + ident.user +
-                    " to " + (to == null ? null : TextUtils.join(", ", to));
+                    " recipients=" + TextUtils.join(", ", recipients);
 
             iservice.setReporter(new TraceOutputStream.IReport() {
                 private int progress = -1;
@@ -707,7 +730,7 @@ public class ServiceSend extends ServiceBase implements SharedPreferences.OnShar
             // Send message
             EntityLog.log(this, "Sending " + via);
             start = new Date().getTime();
-            iservice.getTransport().sendMessage(imessage, to);
+            iservice.getTransport().sendMessage(imessage, recipients.toArray(new Address[0]));
             end = new Date().getTime();
             EntityLog.log(this, "Sent " + via + " elapse=" + (end - start) + " ms");
         } catch (MessagingException ex) {