diff --git a/app/src/main/java/eu/faircode/email/Core.java b/app/src/main/java/eu/faircode/email/Core.java
index ba95cbbd74..edc1080d88 100644
--- a/app/src/main/java/eu/faircode/email/Core.java
+++ b/app/src/main/java/eu/faircode/email/Core.java
@@ -866,7 +866,12 @@ class Core {
             if (keep_days == sync_days)
                 keep_days++;
 
-            Log.i(folder.name + " start sync after=" + sync_days + "/" + keep_days);
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+            boolean sync_unseen = prefs.getBoolean("sync_unseen", false);
+            boolean sync_flagged = prefs.getBoolean("sync_flagged", true);
+
+            Log.i(folder.name + " start sync after=" + sync_days + "/" + keep_days +
+                    " unseen=" + sync_unseen + " sync_flagged=" + sync_flagged);
 
             db.folder().setFolderSyncState(folder.id, "syncing");
 
@@ -915,8 +920,9 @@ class Core {
 
             // Reduce list of local uids
             SearchTerm searchTerm = new ReceivedDateTerm(ComparisonTerm.GE, new Date(sync_time));
-            searchTerm = new OrTerm(searchTerm, new FlagTerm(new Flags(Flags.Flag.SEEN), false));
-            if (ifolder.getPermanentFlags().contains(Flags.Flag.FLAGGED))
+            if (sync_unseen)
+                searchTerm = new OrTerm(searchTerm, new FlagTerm(new Flags(Flags.Flag.SEEN), false));
+            if (sync_flagged && ifolder.getPermanentFlags().contains(Flags.Flag.FLAGGED))
                 searchTerm = new OrTerm(searchTerm, new FlagTerm(new Flags(Flags.Flag.FLAGGED), true));
 
             long search = SystemClock.elapsedRealtime();
diff --git a/app/src/main/java/eu/faircode/email/FragmentOptionsSynchronize.java b/app/src/main/java/eu/faircode/email/FragmentOptionsSynchronize.java
index 70770dc0f1..bba983da98 100644
--- a/app/src/main/java/eu/faircode/email/FragmentOptionsSynchronize.java
+++ b/app/src/main/java/eu/faircode/email/FragmentOptionsSynchronize.java
@@ -54,9 +54,11 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
     private SwitchCompat swSchedule;
     private TextView tvScheduleStart;
     private TextView tvScheduleEnd;
+    private SwitchCompat swUnseen;
+    private SwitchCompat swFlagged;
 
     private final static String[] RESET_OPTIONS = new String[]{
-            "enabled", "poll_interval", "schedule", "schedule_start", "schedule_end"
+            "enabled", "poll_interval", "schedule", "schedule_start", "schedule_end", "sync_unseen", "sync_flagged"
     };
 
     @Override
@@ -74,6 +76,8 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
         swSchedule = view.findViewById(R.id.swSchedule);
         tvScheduleStart = view.findViewById(R.id.tvScheduleStart);
         tvScheduleEnd = view.findViewById(R.id.tvScheduleEnd);
+        swUnseen = view.findViewById(R.id.swUnseen);
+        swFlagged = view.findViewById(R.id.swFlagged);
 
         // Wire controls
 
@@ -153,6 +157,22 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
             }
         });
 
+        swUnseen.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("sync_unseen", checked).apply();
+                ServiceSynchronize.reload(getContext(), false, "sync_unseen=" + checked);
+            }
+        });
+
+        swFlagged.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("sync_flagged", checked).apply();
+                ServiceSynchronize.reload(getContext(), false, "sync_flagged=" + checked);
+            }
+        });
+
         setOptions();
         PreferenceManager.getDefaultSharedPreferences(getContext()).registerOnSharedPreferenceChangeListener(this);
 
@@ -214,6 +234,9 @@ public class FragmentOptionsSynchronize extends FragmentBase implements SharedPr
         swSchedule.setChecked(prefs.getBoolean("schedule", false));
         tvScheduleStart.setText(formatHour(getContext(), prefs.getInt("schedule_start", 0)));
         tvScheduleEnd.setText(formatHour(getContext(), prefs.getInt("schedule_end", 0)));
+
+        swUnseen.setChecked(prefs.getBoolean("sync_unseen", false));
+        swFlagged.setChecked(prefs.getBoolean("sync_flagged", true));
     }
 
     private String formatHour(Context context, int minutes) {
diff --git a/app/src/main/res/layout/fragment_options_synchronize.xml b/app/src/main/res/layout/fragment_options_synchronize.xml
index cf08a02a4b..39a409f496 100644
--- a/app/src/main/res/layout/fragment_options_synchronize.xml
+++ b/app/src/main/res/layout/fragment_options_synchronize.xml
@@ -117,6 +117,28 @@
                 app:layout_constraintEnd_toEndOf="parent"
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@id/tvScheduleStart" />
+
+            <androidx.appcompat.widget.SwitchCompat
+                android:id="@+id/swUnseen"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
+                android:checked="true"
+                android:text="@string/title_advanced_unseen"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/tvScheduleHint"
+                app:switchPadding="12dp" />
+
+            <androidx.appcompat.widget.SwitchCompat
+                android:id="@+id/swFlagged"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
+                android:checked="true"
+                android:text="@string/title_advanced_flagged"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/swUnseen"
+                app:switchPadding="12dp" />
         </androidx.constraintlayout.widget.ConstraintLayout>
     </ScrollView>
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0c3761adf6..bab544ea2c 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -162,6 +162,8 @@
     <string name="title_advanced_enabled">Enabled</string>
     <string name="title_advanced_when">When</string>
     <string name="title_advanced_schedule">Schedule</string>
+    <string name="title_advanced_unseen">All unread messages</string>
+    <string name="title_advanced_flagged">All starred messages</string>
 
     <string name="title_advanced_metered">Use metered connections</string>
     <string name="title_advanced_download">Automatically download messages and attachments on a metered connection up to</string>