diff --git a/app/src/main/java/eu/faircode/email/AdapterFolder.java b/app/src/main/java/eu/faircode/email/AdapterFolder.java
index 20679aba59..2cc7bf528f 100644
--- a/app/src/main/java/eu/faircode/email/AdapterFolder.java
+++ b/app/src/main/java/eu/faircode/email/AdapterFolder.java
@@ -50,9 +50,11 @@ import java.util.Locale;
 import androidx.annotation.NonNull;
 import androidx.appcompat.widget.PopupMenu;
 import androidx.lifecycle.LifecycleOwner;
+import androidx.lifecycle.Observer;
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 import androidx.preference.PreferenceManager;
 import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.ListUpdateCallback;
 import androidx.recyclerview.widget.RecyclerView;
 
@@ -70,12 +72,14 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
 
     private List<TupleFolderEx> all = new ArrayList<>();
     private List<TupleFolderEx> filtered = new ArrayList<>();
+    private List<Long> collapsed = new ArrayList<>();
 
     private static NumberFormat nf = NumberFormat.getNumberInstance();
 
     public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
         private View view;
         private View vwColor;
+        private ImageView ivExpander;
         private View vwLevel;
         private ImageView ivState;
         private ImageView ivNotify;
@@ -88,6 +92,10 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
         private ImageView ivSync;
         private TextView tvKeywords;
         private TextView tvError;
+        private RecyclerView rvChilds;
+
+        private AdapterFolder childs;
+        private TwoStateOwner cowner = new TwoStateOwner(owner);
 
         private final static int action_synchronize_now = 1;
         private final static int action_delete_local = 2;
@@ -101,6 +109,7 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
 
             view = itemView.findViewById(R.id.clItem);
             vwColor = itemView.findViewById(R.id.vwColor);
+            ivExpander = itemView.findViewById(R.id.ivExpander);
             vwLevel = itemView.findViewById(R.id.vwLevel);
             ivState = itemView.findViewById(R.id.ivState);
             ivNotify = itemView.findViewById(R.id.ivNotify);
@@ -113,15 +122,25 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
             ivSync = itemView.findViewById(R.id.ivSync);
             tvKeywords = itemView.findViewById(R.id.tvKeywords);
             tvError = itemView.findViewById(R.id.tvError);
+
+            rvChilds = itemView.findViewById(R.id.rvChilds);
+            LinearLayoutManager llm = new LinearLayoutManager(context);
+            rvChilds.setLayoutManager(llm);
+            rvChilds.setNestedScrollingEnabled(false);
+
+            childs = new AdapterFolder(context, owner);
+            rvChilds.setAdapter(childs);
         }
 
         private void wire() {
             view.setOnClickListener(this);
+            ivExpander.setOnClickListener(this);
             view.setOnLongClickListener(this);
         }
 
         private void unwire() {
             view.setOnClickListener(null);
+            ivExpander.setOnClickListener(null);
             view.setOnLongClickListener(null);
         }
 
@@ -135,6 +154,10 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
             vwColor.setBackgroundColor(folder.accountColor == null ? Color.TRANSPARENT : folder.accountColor);
             vwColor.setVisibility(account < 0 ? View.VISIBLE : View.GONE);
 
+            ivExpander.setImageResource(collapsed.contains(folder.id)
+                    ? R.drawable.baseline_expand_more_24 : R.drawable.baseline_expand_less_24);
+            ivExpander.setVisibility(folder.childs > 0 ? View.VISIBLE : View.INVISIBLE);
+
             if (account > 0) {
                 ViewGroup.LayoutParams lp = vwLevel.getLayoutParams();
                 lp.width = (EntityFolder.USER.equals(folder.type) ? folder.level : 0) * dp12;
@@ -231,6 +254,21 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
 
             tvError.setText(folder.error);
             tvError.setVisibility(folder.error != null ? View.VISIBLE : View.GONE);
+
+            rvChilds.setVisibility(collapsed.contains(folder.id) ? View.GONE : View.VISIBLE);
+
+            cowner.restart();
+            if (folder.childs > 0) {
+                DB db = DB.getInstance(context);
+                cowner.start();
+                db.folder().liveFolders(folder.account, folder.id).observe(cowner, new Observer<List<TupleFolderEx>>() {
+                    @Override
+                    public void onChanged(List<TupleFolderEx> folders) {
+                        childs.set(account, true, folders);
+                    }
+                });
+            } else
+                childs.set(account, true, new ArrayList<TupleFolderEx>());
         }
 
         @Override
@@ -243,11 +281,26 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
             if (folder.tbd != null)
                 return;
 
-            LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(context);
-            lbm.sendBroadcast(
-                    new Intent(ActivityView.ACTION_VIEW_MESSAGES)
-                            .putExtra("account", folder.account)
-                            .putExtra("folder", folder.id));
+            if (view.getId() == R.id.ivExpander) {
+                if (collapsed.contains(folder.id))
+                    collapsed.remove(folder.id);
+                else
+                    collapsed.add(folder.id);
+
+                boolean expanded = !collapsed.contains(folder.id);
+                Log.i("Expanded=" + expanded);
+
+                ivExpander.setImageResource(collapsed.contains(folder.id)
+                        ? R.drawable.baseline_expand_more_24 : R.drawable.baseline_expand_less_24);
+                rvChilds.setVisibility(collapsed.contains(folder.id) ? View.GONE : View.VISIBLE);
+                //notifyItemChanged(pos);
+            } else {
+                LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(context);
+                lbm.sendBroadcast(
+                        new Intent(ActivityView.ACTION_VIEW_MESSAGES)
+                                .putExtra("account", folder.account)
+                                .putExtra("folder", folder.id));
+            }
         }
 
         @Override
diff --git a/app/src/main/java/eu/faircode/email/DaoFolder.java b/app/src/main/java/eu/faircode/email/DaoFolder.java
index 6db5acf163..06c12dcd24 100644
--- a/app/src/main/java/eu/faircode/email/DaoFolder.java
+++ b/app/src/main/java/eu/faircode/email/DaoFolder.java
@@ -56,21 +56,27 @@ public interface DaoFolder {
             ", COUNT(message.id) AS messages" +
             ", SUM(CASE WHEN message.content = 1 THEN 1 ELSE 0 END) AS content" +
             ", SUM(CASE WHEN message.ui_seen = 0 THEN 1 ELSE 0 END) AS unseen" +
+            ", (SELECT COUNT(child.id) FROM folder child WHERE child.parent = folder.id) AS childs" +
             " FROM folder" +
             " LEFT JOIN account ON account.id = folder.account" +
             " LEFT JOIN message ON message.folder = folder.id AND NOT message.ui_hide" +
             " WHERE CASE WHEN :account IS NULL" +
             "  THEN folder.unified AND account.synchronize" +
-            "  ELSE (folder.account = :account AND account.synchronize) OR folder.account IS NULL" +
+            "  ELSE" +
+            "  (folder.account = :account" +
+            "    AND account.synchronize" +
+            "    AND CASE WHEN :parent IS NULL THEN folder.parent IS NULL ELSE folder.parent = :parent END)" +
+            "  OR (folder.account IS NULL AND :parent IS NULL)" +
             " END" +
             " GROUP BY folder.id")
-    LiveData<List<TupleFolderEx>> liveFolders(Long account);
+    LiveData<List<TupleFolderEx>> liveFolders(Long account, Long parent);
 
     @Query("SELECT folder.*" +
             ", account.name AS accountName, account.color AS accountColor, account.state AS accountState" +
             ", COUNT(message.id) AS messages" +
             ", SUM(CASE WHEN message.content = 1 THEN 1 ELSE 0 END) AS content" +
             ", SUM(CASE WHEN message.ui_seen = 0 THEN 1 ELSE 0 END) AS unseen" +
+            ", (SELECT COUNT(child.id) FROM folder child WHERE child.parent = folder.id) AS childs" +
             " FROM folder" +
             " JOIN account ON account.id = folder.account" +
             " LEFT JOIN message ON message.folder = folder.id AND NOT message.ui_hide" +
@@ -91,6 +97,7 @@ public interface DaoFolder {
             ", COUNT(message.id) AS messages" +
             ", SUM(CASE WHEN message.content = 1 THEN 1 ELSE 0 END) AS content" +
             ", SUM(CASE WHEN message.ui_seen = 0 THEN 1 ELSE 0 END) AS unseen" +
+            ", (SELECT COUNT(child.id) FROM folder child WHERE child.parent = folder.id) AS childs" +
             " FROM folder" +
             " LEFT JOIN account ON account.id = folder.account" +
             " LEFT JOIN message ON message.folder = folder.id AND NOT message.ui_hide" +
diff --git a/app/src/main/java/eu/faircode/email/FragmentFolders.java b/app/src/main/java/eu/faircode/email/FragmentFolders.java
index ab59bd51e3..a7e0e2fbea 100644
--- a/app/src/main/java/eu/faircode/email/FragmentFolders.java
+++ b/app/src/main/java/eu/faircode/email/FragmentFolders.java
@@ -239,7 +239,7 @@ public class FragmentFolders extends FragmentBase {
             });
 
         // Observe folders
-        db.folder().liveFolders(account < 0 ? null : account).observe(getViewLifecycleOwner(), new Observer<List<TupleFolderEx>>() {
+        db.folder().liveFolders(account < 0 ? null : account, null).observe(getViewLifecycleOwner(), new Observer<List<TupleFolderEx>>() {
             @Override
             public void onChanged(@Nullable List<TupleFolderEx> folders) {
                 if (folders == null) {
diff --git a/app/src/main/java/eu/faircode/email/TupleFolderEx.java b/app/src/main/java/eu/faircode/email/TupleFolderEx.java
index eef5b2641c..9165387a02 100644
--- a/app/src/main/java/eu/faircode/email/TupleFolderEx.java
+++ b/app/src/main/java/eu/faircode/email/TupleFolderEx.java
@@ -28,6 +28,7 @@ public class TupleFolderEx extends EntityFolder {
     public int messages;
     public int content;
     public int unseen;
+    public int childs;
 
     @Override
     public boolean equals(Object obj) {
@@ -39,7 +40,8 @@ public class TupleFolderEx extends EntityFolder {
                     Objects.equals(this.accountState, other.accountState) &&
                     this.messages == other.messages &&
                     this.content == other.content &&
-                    this.unseen == other.unseen);
+                    this.unseen == other.unseen &&
+                    this.childs == other.childs);
         } else
             return false;
     }
diff --git a/app/src/main/res/layout/item_folder.xml b/app/src/main/res/layout/item_folder.xml
index 9fb240cffe..4729e9928c 100644
--- a/app/src/main/res/layout/item_folder.xml
+++ b/app/src/main/res/layout/item_folder.xml
@@ -20,6 +20,20 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent" />
 
+        <ImageView
+            android:id="@+id/ivExpander"
+            android:layout_width="wrap_content"
+            android:layout_height="0dp"
+            android:layout_gravity="center_vertical|center_horizontal"
+            android:background="?android:attr/selectableItemBackgroundBorderless"
+            android:paddingStart="6dp"
+            android:paddingEnd="6dp"
+            android:src="@drawable/baseline_expand_less_24"
+            android:visibility="visible"
+            app:layout_constraintBottom_toTopOf="@+id/vSeparator"
+            app:layout_constraintStart_toEndOf="@+id/vwColor"
+            app:layout_constraintTop_toTopOf="parent" />
+
         <ImageView
             android:id="@+id/ivState"
             android:layout_width="24dp"
@@ -28,7 +42,7 @@
             android:layout_marginEnd="6dp"
             android:src="@drawable/baseline_cloud_off_24"
             app:layout_constraintBottom_toBottomOf="@+id/tvName"
-            app:layout_constraintStart_toEndOf="@id/vwColor"
+            app:layout_constraintStart_toEndOf="@id/ivExpander"
             app:layout_constraintTop_toTopOf="@+id/tvName" />
 
         <ImageView
@@ -38,7 +52,7 @@
             android:layout_marginStart="12dp"
             android:src="@drawable/baseline_folder_special_24"
             app:layout_constraintBottom_toBottomOf="@+id/tvType"
-            app:layout_constraintStart_toEndOf="@id/vwColor"
+            app:layout_constraintStart_toEndOf="@id/ivExpander"
             app:layout_constraintTop_toTopOf="@+id/tvType" />
 
         <View
@@ -162,7 +176,7 @@
             android:textColor="?attr/colorWarning"
             android:textIsSelectable="true"
             app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toEndOf="@id/vwColor"
+            app:layout_constraintStart_toEndOf="@id/ivExpander"
             app:layout_constraintTop_toBottomOf="@id/tvKeywords" />
 
         <View
@@ -173,5 +187,13 @@
             android:background="?attr/colorSeparator"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/tvError" />
+
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/rvChilds"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/vSeparator" />
     </androidx.constraintlayout.widget.ConstraintLayout>
 </FrameLayout>
\ No newline at end of file