first working version

src/main/java/de/srsoftware/widerhall/mail/SmtpClient.java

@@ -30,21 +30,42 @@ public class SmtpClient {
         this.port = port;
     }
 
-    public void bccForward(String from, Message message, List<String> emails) throws MessagingException {
+
+
+    public void forward(String newSender, List<String> receivers, Message message, String subject, boolean forwardAsAttachment, boolean bcc, String replyTo) throws MessagingException {
         if (session == null) login();
         MimeMessage forward = new MimeMessage(session);
-        forward.setFrom(from);
-        forward.setRecipients(Message.RecipientType.BCC,InternetAddress.parse(String.join(", ",emails)));
-        forward.setSubject(message.getSubject());
+        var oldSender = message.getFrom()[0].toString();
+        if (newSender != null){
+            forward.setFrom(newSender);
+            forward.setSubject(subject+" (from "+oldSender+")");
+        } else {
+            forward.setFrom(oldSender);
+            forward.setSubject(subject);
+        }
+        if (replyTo != null) forward.setReplyTo(InternetAddress.parse(replyTo));
+        var recipientType = bcc ? Message.RecipientType.BCC : Message.RecipientType.TO;
+        forward.setRecipients(recipientType,InternetAddress.parse(String.join(", ",receivers)));
 
         MimeMultipart multipart = new MimeMultipart();
-        MimeBodyPart messageBodyPart = new MimeBodyPart();
+        if (forwardAsAttachment){
+            MimeBodyPart bodyPart = new MimeBodyPart();
+            bodyPart.setText("Find the forwarded message in the attachment(s)!\n");
+            multipart.addBodyPart(bodyPart);
 
-        messageBodyPart.setDataHandler(message.getDataHandler());
-        multipart.addBodyPart(messageBodyPart);
+            // create another body part to contain the message to be forwarded
+            bodyPart = new MimeBodyPart();
+            // forwardedMsg is the MimeMessage object you want to forward as an attachment
+            bodyPart.setContent(message, "message/rfc822");
+            bodyPart.setDisposition(Part.ATTACHMENT);
+            multipart.addBodyPart(bodyPart);
+        } else {
+            MimeBodyPart bodyPart = new MimeBodyPart();
 
+            bodyPart.setDataHandler(message.getDataHandler());
+            multipart.addBodyPart(bodyPart);
+        }
         forward.setContent(multipart);
-
         send(forward);
     }