Fix the sorting when adding mails.

Wino.Mail.ViewModels/Collections/WinoMailCollection.cs

@@ -42,10 +42,21 @@ public class WinoMailCollection : ObservableRecipient, IRecipient<SelectedItemsC
 
     public ReadOnlyObservableGroupedCollection<object, IMailListItem> MailItems { get; }
 
+    private SortingOptionType _sortingType;
+
     /// <summary>
     /// Property that defines how the item sorting should be done in the collection.
     /// </summary>
-    public SortingOptionType SortingType { get; set; }
+    public SortingOptionType SortingType
+    {
+        get => _sortingType;
+        set
+        {
+            _sortingType = value;
+            // Update the comparer's sort mode when sorting type changes
+            listComparer.SortByName = value == SortingOptionType.Sender;
+        }
+    }
 
     /// <summary>
     /// Gets or sets the grouping type for emails.
@@ -79,6 +90,9 @@ public class WinoMailCollection : ObservableRecipient, IRecipient<SelectedItemsC
     {
         MailItems = new ReadOnlyObservableGroupedCollection<object, IMailListItem>(_mailItemSource);
 
+        // Initialize sorting type to default (date-based)
+        SortingType = SortingOptionType.ReceiveDate;
+
         Messenger.Register<SelectedItemsChangedMessage>(this);
     }
 

Wino.Mail.ViewModels/Data/IMailListItem.cs

@@ -9,7 +9,7 @@ namespace Wino.Mail.ViewModels.Data;
 /// Common interface for mail items that can be displayed in a mail list.
 /// Implemented by both MailItemViewModel and ThreadMailItemViewModel.
 /// </summary>
-public interface IMailListItem : IMailHashContainer, INotifyPropertyChanged
+public interface IMailListItem : IMailHashContainer, IMailListItemSorting, INotifyPropertyChanged
 {
     /// <summary>
     /// Gets the latest creation date for sorting purposes.

Wino.Mail.ViewModels/Data/MailItemViewModel.cs

@@ -171,6 +171,10 @@ public partial class MailItemViewModel(MailCopy mailCopy) : ObservableRecipient,
         set => SetProperty(MailCopy.SenderContact.Base64ContactPicture, value, MailCopy, (u, n) => u.SenderContact.Base64ContactPicture = n);
     }
 
+    public DateTime SortingDate => CreationDate;
+
+    public string SortingName => FromName;
+
     public IEnumerable<Guid> GetContainingIds() => [MailCopy.UniqueId];
 
     public IEnumerable<MailItemViewModel> GetSelectedMailItems()

Wino.Mail.ViewModels/Data/ThreadMailItemViewModel.cs

@@ -167,6 +167,10 @@ public partial class ThreadMailItemViewModel : ObservableRecipient, IMailListIte
 
     private MailItemViewModel latestMailViewModel => ThreadEmails.OrderByDescending(e => e.MailCopy?.CreationDate).FirstOrDefault()!;
 
+    public DateTime SortingDate => CreationDate;
+
+    public string SortingName => FromName;
+
     public ThreadMailItemViewModel(string threadId)
     {
         _threadId = threadId;