diff --git a/app/src/main/java/eu/faircode/email/AdapterNavAccount.java b/app/src/main/java/eu/faircode/email/AdapterNavAccount.java
index a00e338690..0b6f668fdf 100644
--- a/app/src/main/java/eu/faircode/email/AdapterNavAccount.java
+++ b/app/src/main/java/eu/faircode/email/AdapterNavAccount.java
@@ -29,6 +29,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.lifecycle.LifecycleOwner;
@@ -59,6 +60,8 @@ public class AdapterNavAccount extends RecyclerView.Adapter<AdapterNavAccount.Vi
     private NumberFormat NF = NumberFormat.getNumberInstance();
     private DateFormat TF;
 
+    private static final int QUOTA_WARNING = 95; // percent
+
     public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
         private View view;
         private ImageView ivItem;
@@ -81,11 +84,13 @@ public class AdapterNavAccount extends RecyclerView.Adapter<AdapterNavAccount.Vi
         private void wire() {
             view.setOnClickListener(this);
             view.setOnLongClickListener(this);
+            ivWarning.setOnClickListener(this);
         }
 
         private void unwire() {
             view.setOnClickListener(null);
             view.setOnLongClickListener(null);
+            ivWarning.setOnClickListener(null);
         }
 
         private void bindTo(TupleAccountEx account) {
@@ -115,11 +120,27 @@ public class AdapterNavAccount extends RecyclerView.Adapter<AdapterNavAccount.Vi
             tvItemExtra.setText(account.last_connected == null ? null : TF.format(account.last_connected));
 
             ivExternal.setVisibility(View.GONE);
-            ivWarning.setVisibility(account.error == null ? View.GONE : View.VISIBLE);
+
+            int percent = Math.round(account.quota_usage * 100f / account.quota_limit);
+            if (account.error != null) {
+                ivWarning.setEnabled(false);
+                ivWarning.setImageResource(R.drawable.twotone_warning_24);
+                ivWarning.setVisibility(View.VISIBLE);
+            } else if (percent > QUOTA_WARNING) {
+                ivWarning.setEnabled(true);
+                ivWarning.setImageResource(R.drawable.twotone_disc_full_24);
+                ivWarning.setVisibility(View.VISIBLE);
+            } else
+                ivWarning.setVisibility(View.GONE);
         }
 
         @Override
         public void onClick(View v) {
+            if (v.getId() == R.id.ivWarning) {
+                ToastEx.makeText(context, R.string.title_legend_quota, Toast.LENGTH_LONG).show();
+                return;
+            }
+
             int pos = getAdapterPosition();
             if (pos == RecyclerView.NO_POSITION)
                 return;
diff --git a/app/src/main/res/drawable/twotone_disc_full_24.xml b/app/src/main/res/drawable/twotone_disc_full_24.xml
new file mode 100644
index 0000000000..97e4d59d85
--- /dev/null
+++ b/app/src/main/res/drawable/twotone_disc_full_24.xml
@@ -0,0 +1,15 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M10,6c-3.31,0 -6,2.69 -6,6s2.69,6 6,6 6,-2.69 6,-6 -2.69,-6 -6,-6zM10,14c-1.1,0 -2,-0.9 -2,-2s0.9,-2 2,-2 2,0.9 2,2 -0.9,2 -2,2z"
+      android:strokeAlpha="0.3"
+      android:fillAlpha="0.3"/>
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M20,14h2v2h-2zM10,4c-4.42,0 -8,3.58 -8,8s3.58,8 8,8 8,-3.58 8,-8 -3.58,-8 -8,-8zM10,18c-3.31,0 -6,-2.69 -6,-6s2.69,-6 6,-6 6,2.69 6,6 -2.69,6 -6,6zM20,7h2v5h-2zM10,10c-1.1,0 -2,0.9 -2,2s0.9,2 2,2 2,-0.9 2,-2 -0.9,-2 -2,-2z"/>
+</vector>
diff --git a/app/src/main/res/layout/fragment_legend_synchronization.xml b/app/src/main/res/layout/fragment_legend_synchronization.xml
index e7b6a5a1f0..582bd8fe59 100644
--- a/app/src/main/res/layout/fragment_legend_synchronization.xml
+++ b/app/src/main/res/layout/fragment_legend_synchronization.xml
@@ -210,6 +210,50 @@
             app:layout_constraintStart_toEndOf="@id/ivDisconnected"
             app:layout_constraintTop_toTopOf="@id/ivDisconnected" />
 
+        <ImageView
+            android:id="@+id/ivConnecting"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:contentDescription="@string/title_legend_connecting"
+            android:padding="12dp"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/ivDisconnected"
+            app:srcCompat="@drawable/twotone_cloud_queue_24" />
+
+        <eu.faircode.email.FixedTextView
+            android:id="@+id/tvConnecting"
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:gravity="center_vertical"
+            android:text="@string/title_legend_connecting"
+            android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+            app:layout_constraintBottom_toBottomOf="@id/ivConnecting"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toEndOf="@id/ivConnecting"
+            app:layout_constraintTop_toTopOf="@id/ivConnecting" />
+
+        <ImageView
+            android:id="@+id/ivConnected"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:contentDescription="@string/title_legend_connected"
+            android:padding="12dp"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/ivConnecting"
+            app:srcCompat="@drawable/twotone_cloud_done_24" />
+
+        <eu.faircode.email.FixedTextView
+            android:id="@+id/tvConnected"
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:gravity="center_vertical"
+            android:text="@string/title_legend_connected"
+            android:textAppearance="@style/TextAppearance.AppCompat.Medium"
+            app:layout_constraintBottom_toBottomOf="@id/ivConnected"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toEndOf="@id/ivConnected"
+            app:layout_constraintTop_toTopOf="@id/ivConnected" />
+
         <ImageView
             android:id="@+id/ivBackoff"
             android:layout_width="wrap_content"
@@ -217,7 +261,7 @@
             android:contentDescription="@string/title_legend_backoff"
             android:padding="12dp"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/ivDisconnected"
+            app:layout_constraintTop_toBottomOf="@id/ivConnected"
             app:srcCompat="@drawable/twotone_update_24" />
 
         <eu.faircode.email.FixedTextView
@@ -244,48 +288,27 @@
             app:srcCompat="@drawable/twotone_info_24" />
 
         <ImageView
-            android:id="@+id/ivConnecting"
+            android:id="@+id/ivQuota"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
-            android:contentDescription="@string/title_legend_connecting"
+            android:contentDescription="@string/title_legend_backoff"
             android:padding="12dp"
+            android:tint="?attr/colorWarning"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/ivBackoff"
-            app:srcCompat="@drawable/twotone_cloud_queue_24" />
+            app:srcCompat="@drawable/twotone_disc_full_24" />
 
         <eu.faircode.email.FixedTextView
-            android:id="@+id/tvConnecting"
+            android:id="@+id/tvQuota"
             android:layout_width="0dp"
             android:layout_height="0dp"
             android:gravity="center_vertical"
-            android:text="@string/title_legend_connecting"
+            android:text="@string/title_legend_quota"
             android:textAppearance="@style/TextAppearance.AppCompat.Medium"
-            app:layout_constraintBottom_toBottomOf="@id/ivConnecting"
+            app:layout_constraintBottom_toBottomOf="@id/ivQuota"
             app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toEndOf="@id/ivConnecting"
-            app:layout_constraintTop_toTopOf="@id/ivConnecting" />
-
-        <ImageView
-            android:id="@+id/ivConnected"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:contentDescription="@string/title_legend_connected"
-            android:padding="12dp"
-            app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/ivConnecting"
-            app:srcCompat="@drawable/twotone_cloud_done_24" />
-
-        <eu.faircode.email.FixedTextView
-            android:id="@+id/tvConnected"
-            android:layout_width="0dp"
-            android:layout_height="0dp"
-            android:gravity="center_vertical"
-            android:text="@string/title_legend_connected"
-            android:textAppearance="@style/TextAppearance.AppCompat.Medium"
-            app:layout_constraintBottom_toBottomOf="@id/ivConnected"
-            app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toEndOf="@id/ivConnected"
-            app:layout_constraintTop_toTopOf="@id/ivConnected" />
+            app:layout_constraintStart_toEndOf="@id/ivQuota"
+            app:layout_constraintTop_toTopOf="@id/ivQuota" />
 
         <ImageView
             android:id="@+id/ivExecuting"
@@ -294,7 +317,7 @@
             android:contentDescription="@string/title_legend_executing"
             android:padding="12dp"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/ivConnected"
+            app:layout_constraintTop_toBottomOf="@id/ivQuota"
             app:srcCompat="@drawable/twotone_dns_24" />
 
         <eu.faircode.email.FixedTextView
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 1e2d677115..1702b89249 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1350,9 +1350,10 @@
     <string name="title_legend_synchronize_off">Synchronize off</string>
     <string name="title_legend_synchronize_poll">Synchronize periodically</string>
     <string name="title_legend_disconnected">Disconnected</string>
-    <string name="title_legend_backoff">Waiting after failure</string>
     <string name="title_legend_connecting">Connecting</string>
     <string name="title_legend_connected">Connected</string>
+    <string name="title_legend_backoff">Waiting after failure</string>
+    <string name="title_legend_quota">Mailbox almost full</string>
     <string name="title_legend_executing">Executing operations</string>
     <string name="title_legend_synchronizing">Synchronizing</string>
     <string name="title_legend_downloading">Downloading</string>