Added remark

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

@@ -0,0 +1,10 @@
+package eu.faircode.email;
+
+import javax.mail.internet.MimePart;
+
+// https://docs.oracle.com/javaee/6/api/javax/mail/internet/package-summary.html
+public class ContentTypeHandler {
+    public static String cleanContentType(MimePart mp, String contentType) {
+        return contentType;
+    }
+}

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

@@ -1163,6 +1163,21 @@ class Core {
             imessage.addHeader(MessageHelper.HEADER_CORRELATION_ID, message.msgid);
 
             imessage.saveChanges();
+            /*
+                javax.mail.internet.ParseException: Unbalanced quoted string
+                    at javax.mail.internet.HeaderTokenizer.collectString(SourceFile:15)
+                    at javax.mail.internet.HeaderTokenizer.getNext(SourceFile:20)
+                    at javax.mail.internet.HeaderTokenizer.next(SourceFile:4)
+                    at javax.mail.internet.HeaderTokenizer.next(SourceFile:1)
+                    at javax.mail.internet.ParameterList.<init>(SourceFile:23)
+                    at javax.mail.internet.ContentType.<init>(SourceFile:17)
+                    at javax.mail.internet.MimeBodyPart.updateHeaders(SourceFile:12)
+                    at javax.mail.internet.MimeBodyPart.updateHeaders(SourceFile:1)
+                    at javax.mail.internet.MimeMultipart.updateHeaders(SourceFile:3)
+                    at javax.mail.internet.MimeBodyPart.updateHeaders(SourceFile:24)
+                    at javax.mail.internet.MimeMessage.updateHeaders(SourceFile:1)
+                    at javax.mail.internet.MimeMessage.saveChanges(SourceFile:3)
+             */
 
             if (flags.contains(Flags.Flag.SEEN))
                 imessage.setFlag(Flags.Flag.SEEN, message.ui_seen);

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

@@ -238,6 +238,7 @@ public class MessageHelper {
         System.setProperty("mail.mime.multipart.ignoremissingendboundary", "true"); // default true
         System.setProperty("mail.mime.multipart.allowempty", "true"); // default false
         System.setProperty("mail.mime.contentdisposition.strict", "false"); // default true
+        //System.setProperty("mail.mime.contenttypehandler", "eu.faircode.email.ContentTypeHandler");
 
         //System.setProperty("mail.imap.parse.debug", "true");