Added remark

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

@@ -1088,7 +1088,6 @@ class Core {
         // - messages in inbox have same id as message sent to self
         // - messages in archive have same id as original
         if (message == null) {
-            // Will fetch headers within database transaction
             String msgid = helper.getMessageID();
             Log.i(folder.name + " searching for " + msgid);
             for (EntityMessage dup : db.message().getMessageByMsgId(folder.account, msgid)) {

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

@@ -84,6 +84,7 @@ public class EntityOperation {
     static final String ATTACHMENT = "attachment";
     static final String SYNC = "sync";
 
+    // These operations should be prepared to be executed twice by both the background and foreground sync
     private static List<String> FOREGROUND = Arrays.asList(KEYWORD, HEADERS, RAW, BODY, ATTACHMENT);
 
     static void queue(Context context, DB db, EntityMessage message, String name, Object... values) {