VB.NET/ASP.NET/ASP MVC - Retrieve email using Microsoft OAuth 2.0 + EWS/Graph API/IMAP4/POP3 protocol from Office 365 in background service¶

Imports System
Imports System.Text
Imports System.IO
Imports System.Net
Imports System.Globalization
Imports EAGetMail

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

Function _postString(ByVal uri As String, ByVal requestData As String) As String
    Dim httpRequest As HttpWebRequest = TryCast(WebRequest.Create(uri), HttpWebRequest)
    httpRequest.Method = "POST"
    httpRequest.ContentType = "application/x-www-form-urlencoded"

    Using requestStream As Stream = httpRequest.GetRequestStream()
        Dim requestBuffer As Byte() = Encoding.UTF8.GetBytes(requestData)
        requestStream.Write(requestBuffer, 0, requestBuffer.Length)
        requestStream.Close()
    End Using

    Try
        Dim httpResponse As HttpWebResponse = TryCast(httpRequest.GetResponse(), HttpWebResponse)
        Using reader As New StreamReader(httpResponse.GetResponseStream())
            Dim responseText = reader.ReadToEnd()
            Return responseText
        End Using

    Catch ex As WebException

        If ex.Status = WebExceptionStatus.ProtocolError Then
            Dim response = TryCast(ex.Response, HttpWebResponse)
            If response IsNot Nothing Then
                Console.WriteLine("HTTP: " & response.StatusCode)
                ' reads response body
                Using reader As StreamReader = New StreamReader(response.GetResponseStream())
                    Dim responseText As String = reader.ReadToEnd()
                    Console.WriteLine(responseText)
                End Using
            End If
        End If

        Throw ex
    End Try

End Function

Public Sub RetrieveEmail()
    Try
        Dim client_id As String = "8f54719b-4070-41ae-91ad-f48e3c793c5f"
        Dim client_secret As String = "cbmYyGQjz[d29wL2ArcgoO7HLwJXL/-."

        ' If your application is not created by Office365 administrator,
        ' please use Office365 directory tenant id, you should ask Offic365 administrator to send it to you.
        ' Office365 administrator can query tenant id in https://portal.azure.com/ - Azure Active Directory.
        Dim tenant As String = "79a42c6f-5a9a-439b-a2ca-7aa1b0ed9776"

        Dim requestData As String = String.Format("client_id={0}&client_secret={1}&scope=https://graph.microsoft.com/.default&grant_type=client_credentials",
                    client_id, client_secret)

        Dim tokenUri As String = String.Format("https://login.microsoftonline.com/{0}/oauth2/v2.0/token", tenant)

        Dim responseText As String = _postString(tokenUri, requestData)
        Dim parser As OAuthResponseParser = New OAuthResponseParser()
        parser.Load(responseText)

        Dim officeUser As String = "user@mydomain.onmicrosoft.com"

        ' 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

        ' Office 365 Graph API address, use access token as password
        Dim oServer As New MailServer("graph.microsoft.com",
                officeUser,
                parser.AccessToken,
                ServerProtocol.MsGraphApi) ' Use Http Graph API Protocol

        ' User OAUTH 2.0
        oServer.AuthType = ServerAuthType.AuthXOAUTH2
        ' Enable SSL/TLS connection,
        oServer.SSLConnection = True

        Console.WriteLine("Connecting {0} ...", oServer.Server)

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

        ' Get New email only, if you want to get all emails, please remove this line
        oClient.GetMailInfosParam.GetMailInfosOptions = GetMailInfosOptionType.NewOnly

        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 email 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 read to prevent retrieving this email again.
            oClient.MarkAsRead(info, True)

            ' If you want to delete current email, please use Delete method instead of MarkAsRead
            ' oClient.Delete(info)

        Next

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

    Catch ep As Exception
        Console.WriteLine(ep.ToString())
    End Try
End Sub

Imports System
Imports System.Text
Imports System.IO
Imports System.Net
Imports System.Globalization
Imports EAGetMail

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

Function _postString(ByVal uri As String, ByVal requestData As String) As String
    Dim httpRequest As HttpWebRequest = TryCast(WebRequest.Create(uri), HttpWebRequest)
    httpRequest.Method = "POST"
    httpRequest.ContentType = "application/x-www-form-urlencoded"

    Using requestStream As Stream = httpRequest.GetRequestStream()
        Dim requestBuffer As Byte() = Encoding.UTF8.GetBytes(requestData)
        requestStream.Write(requestBuffer, 0, requestBuffer.Length)
        requestStream.Close()
    End Using

    Try
        Dim httpResponse As HttpWebResponse = TryCast(httpRequest.GetResponse(), HttpWebResponse)
        Using reader As New StreamReader(httpResponse.GetResponseStream())
            Dim responseText = reader.ReadToEnd()
            Return responseText
        End Using

    Catch ex As WebException

        If ex.Status = WebExceptionStatus.ProtocolError Then
            Dim response = TryCast(ex.Response, HttpWebResponse)
            If response IsNot Nothing Then
                Console.WriteLine("HTTP: " & response.StatusCode)
                ' reads response body
                Using reader As StreamReader = New StreamReader(response.GetResponseStream())
                    Dim responseText As String = reader.ReadToEnd()
                    Console.WriteLine(responseText)
                End Using
            End If
        End If

        Throw ex
    End Try

End Function

Public Sub RetrieveEmail()
    Try
        Dim client_id As String = "8f54719b-4070-41ae-91ad-f48e3c793c5f"
        Dim client_secret As String = "cbmYyGQjz[d29wL2ArcgoO7HLwJXL/-."

        ' If your application is not created by Office365 administrator,
        ' please use Office365 directory tenant id, you should ask Offic365 administrator to send it to you.
        ' Office365 administrator can query tenant id in https://portal.azure.com/ - Azure Active Directory.
        Dim tenant As String = "79a42c6f-5a9a-439b-a2ca-7aa1b0ed9776"

        Dim requestData As String = String.Format("client_id={0}&client_secret={1}&scope=https://outlook.office365.com/.default&grant_type=client_credentials",
                    client_id, client_secret)

        Dim tokenUri As String = String.Format("https://login.microsoftonline.com/{0}/oauth2/v2.0/token", tenant)

        Dim responseText As String = _postString(tokenUri, requestData)
        Dim parser As OAuthResponseParser = New OAuthResponseParser()
        parser.Load(responseText)

        Dim officeUser As String = "user@mydomain.onmicrosoft.com"

        ' 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

        ' Office 365 Server address, use access token as password
        Dim oServer As New MailServer("outlook.office365.com",
                officeUser,
                parser.AccessToken,
                ServerProtocol.ExchangeEWS) ' Use Http EWS Protocol

        ' User OAUTH 2.0
        oServer.AuthType = ServerAuthType.AuthXOAUTH2
        ' Enable SSL/TLS connection,
        oServer.SSLConnection = True

        Console.WriteLine("Connecting {0} ...", oServer.Server)

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

        ' Get New email only, if you want to get all emails, please remove this line
        oClient.GetMailInfosParam.GetMailInfosOptions = GetMailInfosOptionType.NewOnly

        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 email 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 read to prevent retrieving this email again.
            oClient.MarkAsRead(info, True)

            ' If you want to delete current email, please use Delete method instead of MarkAsRead
            ' oClient.Delete(info)

        Next

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

    Catch ep As Exception
        Console.WriteLine(ep.ToString())
    End Try
End Sub

Imports System
Imports System.Text
Imports System.IO
Imports System.Net
Imports System.Globalization
Imports EAGetMail

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

Function _postString(ByVal uri As String, ByVal requestData As String) As String
    Dim httpRequest As HttpWebRequest = TryCast(WebRequest.Create(uri), HttpWebRequest)
    httpRequest.Method = "POST"
    httpRequest.ContentType = "application/x-www-form-urlencoded"

    Using requestStream As Stream = httpRequest.GetRequestStream()
        Dim requestBuffer As Byte() = Encoding.UTF8.GetBytes(requestData)
        requestStream.Write(requestBuffer, 0, requestBuffer.Length)
        requestStream.Close()
    End Using

    Try
        Dim httpResponse As HttpWebResponse = TryCast(httpRequest.GetResponse(), HttpWebResponse)
        Using reader As New StreamReader(httpResponse.GetResponseStream())
            Dim responseText = reader.ReadToEnd()
            Return responseText
        End Using

    Catch ex As WebException

        If ex.Status = WebExceptionStatus.ProtocolError Then
            Dim response = TryCast(ex.Response, HttpWebResponse)
            If response IsNot Nothing Then
                Console.WriteLine("HTTP: " & response.StatusCode)
                ' reads response body
                Using reader As StreamReader = New StreamReader(response.GetResponseStream())
                    Dim responseText As String = reader.ReadToEnd()
                    Console.WriteLine(responseText)
                End Using
            End If
        End If

        Throw ex
    End Try

End Function

Public Sub RetrieveEmail()
    Try
        Dim client_id As String = "8f54719b-4070-41ae-91ad-f48e3c793c5f"
        Dim client_secret As String = "cbmYyGQjz[d29wL2ArcgoO7HLwJXL/-."

        ' If your application is not created by Office365 administrator,
        ' please use Office365 directory tenant id, you should ask Offic365 administrator to send it to you.
        ' Office365 administrator can query tenant id in https://portal.azure.com/ - Azure Active Directory.
        Dim tenant As String = "79a42c6f-5a9a-439b-a2ca-7aa1b0ed9776"

        Dim requestData As String = String.Format("client_id={0}&client_secret={1}&scope=https://outlook.office365.com/.default&grant_type=client_credentials",
                    client_id, client_secret)

        Dim tokenUri As String = String.Format("https://login.microsoftonline.com/{0}/oauth2/v2.0/token", tenant)

        Dim responseText As String = _postString(tokenUri, requestData)
        Dim parser As OAuthResponseParser = New OAuthResponseParser()
        parser.Load(responseText)

        Dim officeUser As String = "user@mydomain.onmicrosoft.com"

        ' 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

        ' Office 365 Server address, use access token as password
        Dim oServer As New MailServer("outlook.office365.com",
                officeUser,
                parser.AccessToken,
                ServerProtocol.Imap4) ' Use IMAP Protocol

        ' User OAUTH 2.0
        oServer.AuthType = ServerAuthType.AuthXOAUTH2
        ' Enable SSL/TLS connection,
        oServer.SSLConnection = True
        ' Set IMAP4 SSL Port
        oServer.Port = 993

        Console.WriteLine("Connecting {0} ...", oServer.Server)

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

        ' Get New email only, if you want to get all emails, please remove this line
        oClient.GetMailInfosParam.GetMailInfosOptions = GetMailInfosOptionType.NewOnly

        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 email 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 read to prevent retrieving this email again.
            oClient.MarkAsRead(info, True)

            ' If you want to delete current email, please use Delete method instead of MarkAsRead
            ' oClient.Delete(info)

        Next

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

    Catch ep As Exception
        Console.WriteLine(ep.ToString())
    End Try
End Sub