Skip to main content

Vb.NET sample for getting the number of Unread messages from an inbox using Impersonation with Exchange Web Services

Although im not a great user of VB any more there does seem to be a bit of a dirth of samples for those people who haven't made the leap to using C#. So here's something that might fill the void for a few people I've put a donwload of this code here the code itself looks like

Imports ewsvbsamp.ews
Imports System.Net
Imports System.Net.Security
Imports System.Security.Cryptography.X509Certificates
Module Module1

Sub Main()
Console.WriteLine(GetUnreadEmailCount("user@domain.com"))
End Sub
Public Function GetUnreadEmailCount(ByVal emailaddress As String) As Integer
Dim UnreadCount As Integer = 0
ServicePointManager.ServerCertificateValidationCallback = New RemoteCertificateValidationCallback(AddressOf ValidateCertificate)
Dim esb As New ExchangeServiceBinding
esb.RequestServerVersionValue = New RequestServerVersion
esb.RequestServerVersionValue.Version = ExchangeVersionType.Exchange2007_SP1
esb.Credentials = New NetworkCredential("user", "password", "domain")
esb.Url = "https://servername/EWS/Exchange.asmx"

Dim csConSid As New ConnectingSIDType
csConSid.PrimarySmtpAddress = emailaddress
Dim exImpersonate As New ExchangeImpersonationType
exImpersonate.ConnectingSID = csConSid
esb.ExchangeImpersonation = exImpersonate

Dim biArray(1) As BaseFolderIdType
Dim dfFolder As New DistinguishedFolderIdType
dfFolder.Id = DistinguishedFolderIdNameType.inbox
biArray(0) = dfFolder
Dim geGetFolder As New GetFolderType
geGetFolder.FolderIds = biArray
geGetFolder.FolderShape = New FolderResponseShapeType
geGetFolder.FolderShape.BaseShape = DefaultShapeNamesType.AllProperties
Dim gfResponse As GetFolderResponseType = esb.GetFolder(geGetFolder)
Dim rmta As ResponseMessageType() = gfResponse.ResponseMessages.Items
Dim rmt As FolderInfoResponseMessageType = DirectCast(rmta(0), FolderInfoResponseMessageType)
If rmt.ResponseClass = ResponseClassType.Success Then
Dim folder As FolderType = DirectCast(rmt.Folders(0), FolderType)
UnreadCount = folder.UnreadCount
End If
Return UnreadCount
End Function

Private Function ValidateCertificate(ByVal sender As Object, ByVal certificate As X509Certificate, ByVal chain As X509Chain, ByVal sslPolicyErrors As SslPolicyErrors) As Boolean
'Return True to force the certificate to be accepted.
Return True
End Function
End Module

Popular posts from this blog

Testing and Sending email via SMTP using Opportunistic TLS and oAuth in Office365 with PowerShell

As well as EWS and Remote PowerShell (RPS) other mail protocols POP3, IMAP and SMTP have had OAuth authentication enabled in Exchange Online (Official announcement here ). A while ago I created  this script that used Opportunistic TLS to perform a Telnet style test against a SMTP server using SMTP AUTH. Now that oAuth authentication has been enabled in office365 I've updated this script to be able to use oAuth instead of SMTP Auth to test against Office365. I've also included a function to actually send a Message. Token Acquisition  To Send a Mail using oAuth you first need to get an Access token from Azure AD there are plenty of ways of doing this in PowerShell. You could use a library like MSAL or ADAL (just google your favoured method) or use a library less approach which I've included with this script . Whatever way you do this you need to make sure that your application registration  https://docs.microsoft.com/en-us/azure/active-directory/develop/quickstart-register-

How to test SMTP using Opportunistic TLS with Powershell and grab the public certificate a SMTP server is using

Most email services these day employ Opportunistic TLS when trying to send Messages which means that wherever possible the Messages will be encrypted rather then the plain text legacy of SMTP.  This method was defined in RFC 3207 "SMTP Service Extension for Secure SMTP over Transport Layer Security" and  there's a quite a good explanation of Opportunistic TLS on Wikipedia  https://en.wikipedia.org/wiki/Opportunistic_TLS .  This is used for both Server to Server (eg MTA to MTA) and Client to server (Eg a Message client like Outlook which acts as a MSA) the later being generally Authenticated. Basically it allows you to have a normal plain text SMTP conversation that is then upgraded to TLS using the STARTTLS verb. Not all servers will support this verb so if its not supported then a message is just sent as Plain text. TLS relies on PKI certificates and the administrative issue s that come around certificate management like expired certificates which is why I wrote th

The MailboxConcurrency limit and using Batching in the Microsoft Graph API

If your getting an error such as Application is over its MailboxConcurrency limit while using the Microsoft Graph API this post may help you understand why. Background   The Mailbox  concurrency limit when your using the Graph API is 4 as per https://docs.microsoft.com/en-us/graph/throttling#outlook-service-limits . This is evaluated for each app ID and mailbox combination so this means you can have different apps running under the same credentials and the poor behavior of one won't cause the other to be throttled. If you compared that to EWS you could have up to 27 concurrent connections but they are shared across all apps on a first come first served basis. Batching Batching in the Graph API is a way of combining multiple requests into a single HTTP request. Batching in the Exchange Mail API's EWS and MAPI has been around for a long time and its common, for email Apps to process large numbers of smaller items for a variety of reasons.  Batching in the Graph is limited to a m
All sample scripts and source code is provided by for illustrative purposes only. All examples are untested in different environments and therefore, I cannot guarantee or imply reliability, serviceability, or function of these programs.

All code contained herein is provided to you "AS IS" without any warranties of any kind. The implied warranties of non-infringement, merchantability and fitness for a particular purpose are expressly disclaimed.