diff --git a/app/src/main/java/eu/faircode/email/AdapterFolder.java b/app/src/main/java/eu/faircode/email/AdapterFolder.java
index 568b9ea92f..d94105f2d1 100644
--- a/app/src/main/java/eu/faircode/email/AdapterFolder.java
+++ b/app/src/main/java/eu/faircode/email/AdapterFolder.java
@@ -178,7 +178,10 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                 tvAfter.setText(null);
                 ivSync.setImageResource(R.drawable.baseline_sync_24);
             } else {
-                tvAfter.setText(String.format("%d/%d", folder.sync_days, folder.keep_days));
+                if (folder.keep_days == Integer.MAX_VALUE)
+                    tvAfter.setText(String.format("%d/∞", folder.sync_days));
+                else
+                    tvAfter.setText(String.format("%d/%d", folder.sync_days, folder.keep_days));
                 ivSync.setImageResource(folder.synchronize ? R.drawable.baseline_sync_24 : R.drawable.baseline_sync_disabled_24);
             }
 
diff --git a/app/src/main/java/eu/faircode/email/FragmentFolder.java b/app/src/main/java/eu/faircode/email/FragmentFolder.java
index 6145f7723c..2823c31995 100644
--- a/app/src/main/java/eu/faircode/email/FragmentFolder.java
+++ b/app/src/main/java/eu/faircode/email/FragmentFolder.java
@@ -55,6 +55,7 @@ public class FragmentFolder extends FragmentEx {
     private CheckBox cbNotify;
     private EditText etSyncDays;
     private EditText etKeepDays;
+    private CheckBox cbKeepAll;
     private Button btnSave;
     private ProgressBar pbSave;
     private ProgressBar pbWait;
@@ -90,6 +91,7 @@ public class FragmentFolder extends FragmentEx {
         cbNotify = view.findViewById(R.id.cbNotify);
         etSyncDays = view.findViewById(R.id.etSyncDays);
         etKeepDays = view.findViewById(R.id.etKeepDays);
+        cbKeepAll = view.findViewById(R.id.cbKeepAll);
         btnSave = view.findViewById(R.id.btnSave);
         pbSave = view.findViewById(R.id.pbSave);
         pbWait = view.findViewById(R.id.pbWait);
@@ -113,6 +115,13 @@ public class FragmentFolder extends FragmentEx {
         // Navigating to individual messages requires notification grouping
         cbNotify.setVisibility(Build.VERSION.SDK_INT >= Build.VERSION_CODES.N ? View.VISIBLE : View.GONE);
 
+        cbKeepAll.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                etKeepDays.setEnabled(!isChecked);
+            }
+        });
+
         btnSave.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -131,7 +140,9 @@ public class FragmentFolder extends FragmentEx {
                 args.putBoolean("poll", cbPoll.isChecked());
                 args.putBoolean("notify", cbNotify.getVisibility() == View.VISIBLE && cbNotify.isChecked());
                 args.putString("sync", etSyncDays.getText().toString());
-                args.putString("keep", etKeepDays.getText().toString());
+                args.putString("keep", cbKeepAll.isChecked()
+                        ? Integer.toString(Integer.MAX_VALUE)
+                        : etKeepDays.getText().toString());
 
                 new SimpleTask<Void>() {
                     @Override
@@ -351,7 +362,10 @@ public class FragmentFolder extends FragmentEx {
                     cbPoll.setChecked(folder == null ? false : folder.poll);
                     cbNotify.setChecked(folder == null ? false : folder.notify);
                     etSyncDays.setText(Integer.toString(folder == null ? EntityFolder.DEFAULT_USER_SYNC : folder.sync_days));
-                    etKeepDays.setText(Integer.toString(folder == null ? EntityFolder.DEFAULT_USER_SYNC : folder.keep_days));
+                    if (folder != null && folder.keep_days == Integer.MAX_VALUE)
+                        cbKeepAll.setChecked(true);
+                    else
+                        etKeepDays.setText(Integer.toString(folder == null ? EntityFolder.DEFAULT_USER_SYNC : folder.keep_days));
                 }
 
                 // Consider previous save as cancelled
diff --git a/app/src/main/res/layout/fragment_folder.xml b/app/src/main/res/layout/fragment_folder.xml
index 2cf906d86e..25cc2258be 100644
--- a/app/src/main/res/layout/fragment_folder.xml
+++ b/app/src/main/res/layout/fragment_folder.xml
@@ -110,6 +110,17 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/cbNotify" />
 
+        <TextView
+            android:id="@+id/tvSyncDaysRemark"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="6dp"
+            android:text="@string/title_sync_days_remark"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            android:textStyle="italic"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tvSyncDays" />
+
         <EditText
             android:id="@+id/etSyncDays"
             android:layout_width="match_parent"
@@ -118,7 +129,7 @@
             android:inputType="number"
             android:textAppearance="@style/TextAppearance.AppCompat.Medium"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tvSyncDays" />
+            app:layout_constraintTop_toBottomOf="@id/tvSyncDaysRemark" />
 
         <TextView
             android:id="@+id/tvKeepDays"
@@ -140,6 +151,14 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/tvKeepDays" />
 
+        <CheckBox
+            android:id="@+id/cbKeepAll"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/title_keep_all"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/etKeepDays" />
+
         <Button
             android:id="@+id/btnSave"
             android:layout_width="wrap_content"
@@ -147,7 +166,7 @@
             android:layout_marginTop="12dp"
             android:text="@string/title_save"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/etKeepDays" />
+            app:layout_constraintTop_toBottomOf="@id/cbKeepAll" />
 
         <ProgressBar
             android:id="@+id/pbSave"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 1afdedcef5..7232d1d0e7 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -187,7 +187,9 @@
     <string name="title_poll_folder">Check periodically instead of continuous synchronize</string>
     <string name="title_notify_folder">Notify new messages</string>
     <string name="title_sync_days">Synchronize messages (days)</string>
+    <string name="title_sync_days_remark">If you have daily internet connectivity, set this to one day after the initial synchronization to reduce battery and data usage</string>
     <string name="title_keep_days">Keep messages (days)</string>
+    <string name="title_keep_all">Keep all messages</string>
     <string name="title_folder_exists">Folder %1$s exists</string>
     <string name="title_folder_delete">Permanently delete this folder and any messages it contains?</string>