Bunch of improvements i dunno.

Wino.Core.Domain/Entities/Mail/MailItemFolder.cs

@@ -40,7 +40,7 @@ public class MailItemFolder : IMailItemFolder
     /// Whether initial synchronization of mail ids is completed for this folder.
     /// Used to determine if we should queue all mail ids first or start downloading from queue.
     /// </summary>
-    public bool IsInitialSyncCompleted { get; set; }
+    public InitialSynchronizationStatus FolderStatus { get; set; }
 
     // For GMail Labels
     public string TextColorHex { get; set; }

Wino.Core.Domain/Entities/Mail/MailItemQueue.cs

@@ -9,6 +9,7 @@ public class MailItemQueue
     public Guid Id { get; set; }
     public Guid AccountId { get; set; }
     public string RemoteServerId { get; set; }
+    public string RemoteFolderId { get; set; }  // For Outlook per-folder sync
     public bool IsProcessed { get; set; }
     public int FailedCount { get; set; }
     public DateTime CreatedAt { get; set; }