Capitilize first letter of folder names if all capital for IMAP.

Wino.Core/Extensions/MailkitExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using MailKit;
 using Wino.Core.Domain.Entities;
 
@@ -8,14 +9,28 @@ namespace Wino.Core.Extensions
     {
         public static MailItemFolder GetLocalFolder(this IMailFolder mailkitMailFolder)
         {
+            bool isAllCapital = mailkitMailFolder.Name?.All(a => char.IsUpper(a)) ?? false;
+
             return new MailItemFolder()
             {
                 Id = Guid.NewGuid(),
-                FolderName = mailkitMailFolder.Name,
+                FolderName = isAllCapital ? mailkitMailFolder.Name.OnlyCapitilizeFirstLetter() : mailkitMailFolder.Name,
                 RemoteFolderId = mailkitMailFolder.FullName,
                 ParentRemoteFolderId = mailkitMailFolder.ParentFolder?.FullName,
                 SpecialFolderType = Domain.Enums.SpecialFolderType.Other
             };
         }
+
+        public static string OnlyCapitilizeFirstLetter(this string s)
+        {
+            if (string.IsNullOrEmpty(s))
+                return string.Empty;
+
+            s = s.ToLower();
+
+            char[] a = s.ToCharArray();
+            a[0] = char.ToUpper(a[0]);
+            return new string(a);
+        }
     }
 }