Separate messages of different accounts

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

@@ -49,7 +49,7 @@ public interface DaoMessage {
             " JOIN folder ON folder.id = message.folder" +
             " WHERE account.`synchronize`" +
             " AND (NOT message.ui_hide OR :debug)" +
-            " GROUP BY CASE WHEN message.thread IS NULL THEN message.id ELSE message.thread END" +
+            " GROUP BY account.id, CASE WHEN message.thread IS NULL THEN message.id ELSE message.thread END" +
             " HAVING SUM(unified) > 0" +
             " ORDER BY message.received DESC")
     DataSource.Factory<Integer, TupleMessageEx> pagedUnifiedInbox(boolean debug);