User is not reading messages

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

@@ -3826,6 +3826,13 @@ class Core {
             cal_keep.set(Calendar.SECOND, 0);
             cal_keep.set(Calendar.MILLISECOND, 0);
 
+            Calendar cal_keep_unseen = Calendar.getInstance();
+            cal_keep_unseen.add(Calendar.DAY_OF_MONTH, -keep_days * 2);
+            cal_keep_unseen.set(Calendar.HOUR_OF_DAY, 0);
+            cal_keep_unseen.set(Calendar.MINUTE, 0);
+            cal_keep_unseen.set(Calendar.SECOND, 0);
+            cal_keep_unseen.set(Calendar.MILLISECOND, 0);
+
             long sync_time = cal_sync.getTimeInMillis();
             if (sync_time < 0)
                 sync_time = 0;
@@ -3834,6 +3841,10 @@ class Core {
             if (keep_time < 0)
                 keep_time = 0;
 
+            long keep_time_unseen = cal_keep_unseen.getTimeInMillis();
+            if (keep_time_unseen < 0)
+                keep_time_unseen = 0;
+
             Log.i(folder.name + " sync=" + new Date(sync_time) + " keep=" + new Date(keep_time));
 
             // Delete old local messages
@@ -3852,7 +3863,7 @@ class Core {
                             EntityOperation.queue(context, message, EntityOperation.MOVE, trash.id);
                 }
             } else {
-                int old = db.message().deleteMessagesBefore(folder.id, delete_time, keep_time, delete_unseen);
+                int old = db.message().deleteMessagesBefore(folder.id, delete_time, keep_time, keep_time_unseen, delete_unseen);
                 Log.i(folder.name + " local old=" + old);
             }
 

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

@@ -1016,11 +1016,11 @@ public interface DaoMessage {
             " WHERE folder = :folder" +
             " AND received < :keep_time" +
             " AND NOT uid IS NULL" +
-            " AND (ui_seen OR :unseen)" +
+            " AND (ui_seen OR received < :keep_time_unseen OR :unseen)" +
             " AND NOT ui_flagged" +
             " AND stored < :sync_time" + // moved, browsed
             " AND (ui_snoozed IS NULL OR ui_snoozed = " + Long.MAX_VALUE + ")")
-    int deleteMessagesBefore(long folder, long sync_time, long keep_time, boolean unseen);
+    int deleteMessagesBefore(long folder, long sync_time, long keep_time, long keep_time_unseen, boolean unseen);
 
     @Transaction
     @Query("DELETE FROM message" +