Exchange Web Services (EWS) FindItems within All Folders

Answered on http://social.technet.microsoft.com/Forums/en-US/exchangesvrdevelopment/thread/8c71ace4-43d2-4ba2-88f2-16376dad828f.

If all you need is a collection of all folders and subfolders on the server, You can page your requests and get the entire folder hierarchy from the server in just a few calls. The key is the FolderView.Traversal property.

For example, for an Exchange mailbox with ~1,300 folders the code below only makes 2 requests. You can set your page size to whatever you like, as long as you stay at or below the server limit.

FYI: Exchange Online (Office365) caps at a maximum of 1,000 items in a response. I haven't tested, so I can't speak for any similar limits when querying an on-premises Exchange Server.

Imports Exchange = Microsoft.Exchange.WebServices.Data

Friend Module Main
  Public Sub Main()
    Dim oService As Exchange.ExchangeService
    Dim oUsers As Dictionary(Of String, User)

    oUsers = New Dictionary(Of String, User)
    oUsers.Add("User1", New User("[email protected]", "Some-Fancy-Password1"))
    oUsers.Add("User2", New User("[email protected]", "Some-Fancy-Password2"))

    oUsers.ToList.ForEach(Sub(Credential As KeyValuePair(Of String, User))
                            File.Delete(LOG_FILE_PATH.ToFormat(Credential.Key))
                          End Sub)

    oUsers.ToList.ForEach(Sub(Credential As KeyValuePair(Of String, User))
                            LogFileName = Credential.Key

                            Console.WriteLine("Getting message counts for mailbox [{0}]...", LogFileName)
                            Console.WriteLine()

                            oService = Service.ConnectToService(Credential.Value)

                            GetAllFolders(oService, LOG_FILE_PATH.ToFormat(Credential.Key))

                            Console.Clear()
                          End Sub)

    Console.WriteLine()
    Console.Write("Press any key to exit...")
    Console.ReadKey()
  End Sub



  Private Sub GetAllFolders(Service As Exchange.ExchangeService, LogFilePath As String)
    Dim oIsHidden As Exchange.ExtendedPropertyDefinition
    Dim oFolders As List(Of Exchange.Folder)
    Dim oResults As Exchange.FindFoldersResults
    Dim lHasMore As Boolean
    Dim oChild As Exchange.Folder
    Dim oView As Exchange.FolderView

    Dim _
      nPageSize,
      nOffSet As Short

    Dim _
      oPaths,
      oPath As List(Of String)

    oIsHidden = New Exchange.ExtendedPropertyDefinition(&H10F4, Exchange.MapiPropertyType.Boolean)
    nPageSize = 1000
    oFolders = New List(Of Exchange.Folder)
    lHasMore = True
    nOffSet = 0

    Do While lHasMore
      oView = New Exchange.FolderView(nPageSize, nOffSet, Exchange.OffsetBasePoint.Beginning)
      oView.PropertySet = New Exchange.PropertySet(Exchange.BasePropertySet.IdOnly)
      oView.PropertySet.Add(oIsHidden)
      oView.PropertySet.Add(Exchange.FolderSchema.ParentFolderId)
      oView.PropertySet.Add(Exchange.FolderSchema.DisplayName)
      oView.PropertySet.Add(Exchange.FolderSchema.FolderClass)
      oView.PropertySet.Add(Exchange.FolderSchema.TotalCount)
      oView.Traversal = Exchange.FolderTraversal.Deep

      oResults = Service.FindFolders(Exchange.WellKnownFolderName.MsgFolderRoot, oView)
      oFolders.AddRange(oResults.Folders)

      lHasMore = oResults.MoreAvailable

      If lHasMore Then
        nOffSet += nPageSize
      End If
    Loop

    oFolders.RemoveAll(Function(Folder) Folder.ExtendedProperties(0).Value = True)
    oFolders.RemoveAll(Function(Folder) Folder.FolderClass <> "IPF.Note")

    oPaths = New List(Of String)

    oFolders.ForEach(Sub(Folder)
                       oChild = Folder
                       oPath = New List(Of String)

                       Do
                         oPath.Add(oChild.DisplayName)
                         oChild = oFolders.SingleOrDefault(Function(Parent) Parent.Id.UniqueId = oChild.ParentFolderId.UniqueId)
                       Loop While oChild IsNot Nothing

                       oPath.Reverse()
                       oPaths.Add("{0}{1}{2}".ToFormat(Join(oPath.ToArray, DELIMITER), vbTab, Folder.TotalCount))
                     End Sub)

    oPaths.RemoveAll(Function(Path) Path.StartsWith("Sync Issues"))

    File.WriteAllText(LogFilePath, Join(oPaths.ToArray, vbCrLf))
  End Sub



  Private LogFileName As String

  Private Const LOG_FILE_PATH As String = "D:\Emails\Remote{0}.txt"
  Private Const DELIMITER As String = "\"
End Module



Friend Class Service
  Public Shared Function ConnectToService(User As User) As Exchange.ExchangeService
    Return Service.ConnectToService(User, Nothing)
  End Function



  Public Shared Function ConnectToService(User As User, Listener As Exchange.ITraceListener) As Exchange.ExchangeService
    Dim oService As Exchange.ExchangeService

    oService = New Exchange.ExchangeService(Exchange.ExchangeVersion.Exchange2013_SP1)
    oService.Credentials = New NetworkCredential(User.EmailAddress, User.Password)
    oService.AutodiscoverUrl(User.EmailAddress, AddressOf RedirectionUrlValidationCallback)

    If Listener IsNot Nothing Then
      oService.TraceListener = Listener
      oService.TraceEnabled = True
      oService.TraceFlags = Exchange.TraceFlags.All
    End If

    Return oService
  End Function



  Private Shared Function RedirectionUrlValidationCallback(RedirectionUrl As String) As Boolean
    With New Uri(RedirectionUrl)
      Return .Scheme.ToLower = "https"
    End With
  End Function
End Class



Friend Class User
  Public Sub New(EmailAddress As String)
    _EmailAddress = EmailAddress
    _Password = New SecureString
  End Sub



  Public Sub New(EmailAddress As String, Password As String)
    _EmailAddress = EmailAddress
    _Password = New SecureString

    Password.ToList.ForEach(Sub(Chr As Char)
                              Me.Password.AppendChar(Chr)
                            End Sub)

    Password.MakeReadOnly()
  End Sub



  Public Shared Function GetUser() As User
    Dim sEmailAddress As String
    Dim oUserInput As ConsoleKeyInfo

    Console.Write("Enter email address: ")
    sEmailAddress = Console.ReadLine
    Console.Write("Enter password: ")

    GetUser = New User(sEmailAddress)

    While True
      oUserInput = Console.ReadKey(True)

      If oUserInput.Key = ConsoleKey.Enter Then
        Exit While

      ElseIf oUserInput.Key = ConsoleKey.Escape Then
        GetUser.Password.Clear()

      ElseIf oUserInput.Key = ConsoleKey.Backspace Then
        If GetUser.Password.Length <> 0 Then
          GetUser.Password.RemoveAt(GetUser.Password.Length - 1)
        End If

      Else
        GetUser.Password.AppendChar(oUserInput.KeyChar)
        Console.Write("*")

      End If
    End While

    If GetUser.Password.Length = 0 Then
      GetUser = Nothing
    Else
      GetUser.Password.MakeReadOnly()
      Console.WriteLine()
    End If
  End Function



  Public ReadOnly Property EmailAddress As String

  Public ReadOnly Property Password As SecureString
End Class



Friend Class TraceListener
  Implements Exchange.ITraceListener

  Public Sub Trace(TraceType As String, TraceMessage As String) Implements Exchange.ITraceListener.Trace
    File.AppendAllText("{0}.txt".ToFormat(Path.Combine("D:\Emails\TraceOutput", Guid.NewGuid.ToString("D"))), TraceMessage)
  End Sub
End Class

I have found some information on the AllItems folder within Exchange over at Glen's blog. I have ported the PowerShell script to C# as shown below.

private static void SearchItems()
{
    ExtendedPropertyDefinition allFoldersType = 
        new ExtendedPropertyDefinition(13825, MapiPropertyType.Integer);

    FolderId rootFolderId = new FolderId(WellKnownFolderName.Root);
    FolderView folderView = new FolderView(1000);
    folderView.Traversal = FolderTraversal.Shallow;

    SearchFilter searchFilter1 = new SearchFilter.IsEqualTo(allFoldersType, "2");
    SearchFilter searchFilter2 = new SearchFilter.IsEqualTo(FolderSchema.DisplayName, "allitems");

    SearchFilter.SearchFilterCollection searchFilterCollection = 
        new SearchFilter.SearchFilterCollection(LogicalOperator.And);
    searchFilterCollection.Add(searchFilter1);
    searchFilterCollection.Add(searchFilter2);

    FindFoldersResults findFoldersResults = 
        _service.FindFolders(rootFolderId, searchFilterCollection, folderView);

    if (findFoldersResults.Folders.Count > 0)
    {
        Folder allItemsFolder = findFoldersResults.Folders[0];
        Console.WriteLine("Folder:\t" + allItemsFolder.DisplayName);

        ItemView iv = new ItemView(1000);
        FindItemsResults<Item> findResults = 
            allItemsFolder.FindItems("System.Message.DateReceived:01/01/2011..01/31/2011", iv);

        foreach (Item item in findResults)
        {
            Console.WriteLine("Subject:\t" + item.Subject);
            Console.WriteLine("Received At:\t\t" + item.DateTimeReceived.ToString("dd MMMM yyyy"));
            Console.WriteLine("Is New:\t\t" + item.IsNew.ToString());
            Console.WriteLine("Has Attachments:\t\t" + item.HasAttachments.ToString());
            Console.WriteLine();
        }
    }

    Console.WriteLine("Press Enter to continue");
    Console.ReadLine();
}