Retrieve Email from Exchange Server with Web Service (EWS) in VB.NET

In previous section, I introduced how to retrieve email from IMAP4 server. In this section, I will introduce the Exchange Web Service (EWS) protocol (Exchange 2007-2019/Office365).

Introduction

Exchange Web Service (EWS) protocol is similar with IMAP4 protocol. First of all, it supports retrieving email from different mail folder and folder management. Secondly, Exchange Web Service supports mail read flag management. Therefore, we can do more things with Exchange server. To better understand the Exchange Web Service protocol, please see the following examples.

Exchange Server supports POP3/IMAP4 protocol as well, but in Exchange 2007 or later version, POP3/IMAP4 service is disabled by default. If you don’t want to use POP3/IMAP4 to download email from Exchange Server, you can use Exchange Web Service (Exchange 2007/2010/2013/2016 or later version) or WebDAV (Exchange 2000/2003) protocol.

Office 365 also supports EWS protocol.

Note

Remarks: All of examples in this section are based on first section: A simple VB.NET project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference to your project.

[VB.NET Example - Retrieve email from Exchange INBOX]

The following example codes demonstrate how to download email from Exchange 2007/2010/2013/2016 server default mailbox using EWS protocol. In order to run it correctly, please change email server, user, password, folder, file name values.

Note

To get the full sample projects, please refer to Samples section.

Imports System.Globalization
Imports System.Text
Imports System.IO
Imports EAGetMail 'imports EAGetMail namespace

Module Module1

    Function _generateFileName(ByVal sequence As Integer) As String
        Dim currentDateTime As DateTime = DateTime.Now
        Return String.Format("{0}-{1:000}-{2:000}.eml",
                            currentDateTime.ToString("yyyyMMddHHmmss", New CultureInfo("en-US")),
                            currentDateTime.Millisecond,
                            sequence)
    End Function

    Sub Main()

        Try
            ' Create a folder named "inbox" under current directory
            ' to save the email retrieved.
            Dim localInbox As String = String.Format("{0}\inbox", Directory.GetCurrentDirectory())

            ' If the folder is not existed, create it.
            If Not Directory.Exists(localInbox) Then
                Directory.CreateDirectory(localInbox)
            End If

            ' Please use domain\user or full email address as the user name
            Dim oServer As New MailServer("exch.emailarchitect.net",
                        "tester@emailarchitect.net",
                        "testpassword",
                        ServerProtocol.ExchangeEWS)

            ' By default, Exchange Web Service (EWS) requires SSL connection
            ' Please ignore Port property for EWS and WebDAV protocol
            oServer.SSLConnection = True

            Console.WriteLine("Connecting server ...")

            Dim oClient As New MailClient("TryIt")
            oClient.Connect(oServer)

            Dim infos As MailInfo() = oClient.GetMailInfos()
            Console.WriteLine("Total {0} email(s)", infos.Length)

            For i As Integer = 0 To infos.Length - 1
                Dim info As MailInfo = infos(i)
                Console.WriteLine("Index: {0}; Size: {1}; UIDL: {2}",
                        info.Index, info.Size, info.UIDL)

                ' Retrieve email from Exchange server
                Dim oMail As Mail = oClient.GetMail(info)

                Console.WriteLine("From: {0}", oMail.From.ToString())
                Console.WriteLine("Subject: {0}" & vbCr & vbLf, oMail.Subject)

                ' Generate an unqiue email file name based on date time.
                Dim fileName As String = _generateFileName(i + 1)
                Dim fullPath As String = String.Format("{0}\{1}", localInbox, fileName)

                ' Save email to local disk
                oMail.SaveAs(fullPath, True)

                ' Mark email as deleted from Exchange server.
                oClient.Delete(info)

            Next

            ' Quit and expunge emails marked as deleted from Exchange server.
            oClient.Quit()
            Console.WriteLine("Completed!")

        Catch ep As Exception
            Console.WriteLine(ep.Message)
        End Try

    End Sub
End Module

Because Exchange Web Service protocol supports folder access, so we can retrieve email from other mailbox rather than default “INBOX”. POP3 protocol doesn’t support this feature.

[VB.NET Example - Retrieve email from “Deleted Items”]

The following example codes demonstrate how to retrieve emails from “Deleted Items” in an Exchange account.

Note

To get the full sample projects, please refer to Samples section.

Imports System.Globalization
Imports System.Text
Imports System.IO
Imports EAGetMail 'imports EAGetMail namespace

Module Module1

    ' if you want to search sub folder, use parentfolder\subfolder as folderPath
    ' for example: inbox\mysubfolder
    Function FindFolder(ByVal folderPath As String, ByRef folders As Imap4Folder()) As Imap4Folder
        For i As Integer = 0 To folders.Length - 1
            Dim folder As Imap4Folder = folders(i)
            ' Folder was found.
            If String.Compare(folder.LocalPath, folderPath, True) = 0 Then
                Return folder
            End If

            folder = FindFolder(folderPath, folder.SubFolders)
            If Not (folder Is Nothing) Then
                Return folder
            End If
        Next

        ' No folder found
        Return Nothing
    End Function

    Function _generateFileName(ByVal sequence As Integer) As String
        Dim currentDateTime As DateTime = DateTime.Now
        Return String.Format("{0}-{1:000}-{2:000}.eml",
                            currentDateTime.ToString("yyyyMMddHHmmss", New CultureInfo("en-US")),
                            currentDateTime.Millisecond,
                            sequence)
    End Function

    Sub Main()

        Try
            ' Create a folder named "inbox" under current directory
            ' to save the email retrieved.
            Dim localInbox As String = String.Format("{0}\inbox", Directory.GetCurrentDirectory())

            ' If the folder is not existed, create it.
            If Not Directory.Exists(localInbox) Then
                Directory.CreateDirectory(localInbox)
            End If

            ' Please use domain\user or full email address as the user name
            Dim oServer As New MailServer("exch.emailarchitect.net",
                        "tester@emailarchitect.net",
                        "testpassword",
                        ServerProtocol.ExchangeEWS)

            ' By default, Exchange Web Service (EWS) requires SSL connection
            ' Please ignore Port property for EWS and WebDAV protocol
            oServer.SSLConnection = True

            Console.WriteLine("Connecting server ...")

            Dim oClient As New MailClient("TryIt")
            oClient.Connect(oServer)

            ' Lookup folder based on path.
            Dim folder As Imap4Folder = FindFolder("Deleted Items", oClient.GetFolders())
            If folder Is Nothing Then
                Throw New Exception("Folder was not found")
            End If

            ' Select this folder
            oClient.SelectFolder(folder)

            Dim infos As MailInfo() = oClient.GetMailInfos()
            Console.WriteLine("Total {0} email(s)", infos.Length)

            For i As Integer = 0 To infos.Length - 1
                Dim info As MailInfo = infos(i)
                Console.WriteLine("Index: {0}; Size: {1}; UIDL: {2}",
                        info.Index, info.Size, info.UIDL)

                ' Retrieve email from Exchange server
                Dim oMail As Mail = oClient.GetMail(info)

                Console.WriteLine("From: {0}", oMail.From.ToString())
                Console.WriteLine("Subject: {0}" & vbCr & vbLf, oMail.Subject)

                ' Generate an unqiue email file name based on date time.
                Dim fileName As String = _generateFileName(i + 1)
                Dim fullPath As String = String.Format("{0}\{1}", localInbox, fileName)

                ' Save email to local disk
                oMail.SaveAs(fullPath, True)

                ' Mark email as deleted from Exchange server.
                oClient.Delete(info)

            Next

            ' Quit and expunge emails marked as deleted from Exchange server.
            oClient.Quit()
            Console.WriteLine("Completed!")

        Catch ep As Exception
            Console.WriteLine(ep.Message)
        End Try

    End Sub
End Module

Next Section

At next section I will introduce how to retrieve email from Exchange Server with WebDAV protocol.

Appendix

Comments

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