Added hint text

app/src/main/res/layout/dialog_sync.xml

@@ -85,5 +85,16 @@
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/tvRemark" />
+
+        <eu.faircode.email.FixedTextView
+            android:id="@+id/tvRemark3"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="12dp"
+            android:text="@string/title_synchronize_more_hint3"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tvRemark2" />
     </androidx.constraintlayout.widget.ConstraintLayout>
 </eu.faircode.email.ScrollViewEx>

app/src/main/res/values/strings.xml

@@ -1006,6 +1006,7 @@
         Messages will be fetched as fast as the email server can deliver them and stored as fast as the device can store and index them.
         The limiting factor is usually the speed of the device\'s internal storage space.
     </string>
+    <string name="title_synchronize_more_hint3">Please keep in mind that storing a lot of messages (ten thousand or more) on your device can cause delays because the internal storage space is not infinitely fast.</string>
     <string name="title_synchronize_enabled">Synchronize</string>
     <string name="title_synchronize_batch_enable">Enable synchronization</string>
     <string name="title_synchronize_batch_disable">Disable synchronization</string>