Private ExchangeBinding As New ExchangeServiceBinding
Public Sub New(ByVal UserName As String, ByVal Password As String, ByVal Domain As String, ByVal URL As String)
    ExchangeBinding.Credentials = New NetworkCredential(UserName, Password, Domain)
    ExchangeBinding.Url = URL
End Sub

Dim returnInboxMessageIds As ArrayOfRealItemsType = Nothing
    Dim errMsg As String = String.Empty

    'Create the request and specify the travesal type.
    Dim FindItemRequest As FindItemType
    FindItemRequest = New FindItemType
    FindItemRequest.Traversal = ItemQueryTraversalType.Shallow

    'Define which item properties are returned in the response.
    Dim ItemProperties As ItemResponseShapeType
    ItemProperties = New ItemResponseShapeType
    ItemProperties.BaseShape = DefaultShapeNamesType.IdOnly

    'Add properties shape to the request.
    FindItemRequest.ItemShape = ItemProperties

    'Identify which folders to search to find items.
    Dim FolderIDArray(0) As DistinguishedFolderIdType
    FolderIDArray(0) = New DistinguishedFolderIdType
    FolderIDArray(0).Id = DistinguishedFolderIdNameType.inbox

    'Add folders to the request.
    FindItemRequest.ParentFolderIds = FolderIDArray

    Try
        'Send the request and get the response.
        Dim FindItemResponse As FindItemResponseType
        FindItemResponse = ExchangeBinding.FindItem(FindItemRequest)

        'Get the response messages.
        Dim ResponseMessage As ResponseMessageType()
        ResponseMessage = FindItemResponse.ResponseMessages.Items

        Dim FindItemResponseMessage As FindItemResponseMessageType

        If ResponseMessage(0).ResponseClass = ResponseClassType.Success Then

            FindItemResponseMessage = ResponseMessage(0)
            returnInboxMessageIds = FindItemResponseMessage.RootFolder.Item

        Else

            '' Server error
            Dim responseClassStr As String = [Enum].GetName(GetType(ExchangeWebServices.ResponseClassType), ResponseMessage(0).ResponseClass).ToString
            Dim responseCodeStr As String = [Enum].GetName(GetType(ExchangeWebServices.ResponseCodeType), ResponseMessage(0).ResponseCode).ToString
            Dim messageTextStr As String = ResponseMessage(0).MessageText.ToString
            Dim thisErrMsg As String = String.Format("ExchangeWebServices Inbox Error: {0}, {1}, {2}", responseClassStr, responseCodeStr, messageTextStr)
            errMsg = If(errMsg.Equals(String.Empty), String.Empty, errMsg & "; ") & thisErrMsg

        End If

    Catch ex As Exception
        errMsg = If(errMsg.Equals(String.Empty), String.Empty, errMsg & "; ") & ex.Message
    End Try

    If Not errMsg.Equals(String.Empty) Then
        returnInboxMessageIds = Nothing
        Throw New System.Exception(errMsg)
    End If

    Return returnInboxMessageIds

End Function

-ExchangeServiceBinding
-ArrayOfRealItemsType
-FindItemType
-ItemQueryTraversalType
-ItemResponseShapeType
-DefaultShapeNamesType
-DistinguishedFolderIdType
-DistinguishedFolderIdNameType
-FindItemResponseType
-ResponseMessageType()
-FindItemResponseMessageType
-ResponseClassType