diff --git a/Elwig/App.xaml.cs b/Elwig/App.xaml.cs
index a0c51e4..9bf76a2 100644
--- a/Elwig/App.xaml.cs
+++ b/Elwig/App.xaml.cs
@@ -252,7 +252,7 @@ namespace Elwig {
         }
 
         public static MailWindow FocusMailWindow(int? year = null) {
-            return FocusWindow<MailWindow>(() => new(year));
+            return FocusWindow<MailWindow>(() => new(year), w => year == null || w.Year == year);
         }
     }
 }
diff --git a/Elwig/Windows/MailWindow.xaml.cs b/Elwig/Windows/MailWindow.xaml.cs
index d5d4706..ca1f1fe 100644
--- a/Elwig/Windows/MailWindow.xaml.cs
+++ b/Elwig/Windows/MailWindow.xaml.cs
@@ -52,7 +52,7 @@ namespace Elwig.Windows {
             CreditNote.Name,
         ];
 
-        protected readonly int? Year;
+        public readonly int? Year;
         public ObservableCollection<SelectedDoc> SelectedDocs = [];
         public IEnumerable<Member> Recipients = [];
 
@@ -102,7 +102,7 @@ namespace Elwig.Windows {
         public MailWindow(int? year = null) {
             InitializeComponent();
             Year = year ?? Context.Seasons.OrderBy(s => s.Year).LastOrDefault()?.Year;
-            Title = $"Rundschreiben {Year} - Elwig";
+            Title = $"Rundschreiben - Lese {Year} - Elwig";
 
             AvaiableDocumentsList.ItemsSource = AvaiableDocuments;
             SelectedDocumentsList.ItemsSource = SelectedDocs;
@@ -559,7 +559,7 @@ namespace Elwig.Windows {
 
         public void AddDeliveryConfirmation() {
             AvaiableDocumentsList.SelectedIndex = 1;
-            if (AvaiableDocumentsList.SelectedItem is not string s)
+            if (AvaiableDocumentsList.SelectedItem is not string s || SelectedDocs.Any(d => d.Type == DocType.DeliveryConfirmation))
                 return;
             SelectedDocs.Add(new(DocType.DeliveryConfirmation, s, ((int)Year!, DocumentNonDeliverersInput.IsChecked == true)));
             SelectedDocumentsList.SelectedIndex = SelectedDocs.Count - 1;