How to Access SMTP & IMAP Server using OAuth inside .NET Apps

This technical tip explains how .NET developers can Access SMTP & IMAP Server using OAuth inside .NET Applications. Aspose.Email for .NET can be used to access SMTP and IMAP servers. OAuth support for Google mail is implemented only for version 2.0 as OAuth 1.0 has been officially deprecated as of April 20, 2012. At this moment, Google supports OAuth only for the Google Apps Platform and public mail accounts can't be used with the OAuth mechanism. When a new Google Apps account is created, a new "Installed Application" should be registered for this account for testing in the APIs Console. Free trial accounts can be created, provided by Google Apps for Business.
//your code here...//[C# Code Sample] static void Main(string[] args) { // The authorizationCode should be replaced with your value. // To get authorizationCode use the URL bellow: // string authorizationCode = "4/zx4_I4ZhhUdmgLdsejpjeMkwAAMs.kk7o1Qx9U28VOl05ti8ZT3Y1uIlidQI"; // authorizationCode should be replaced with new value !!!!!!! string accessToken = GetAccessToken(authorizationCode); AccessSMTPServer(accessToken); AccessIMAPServer(accessToken); } static void AccessSMTPServer(string accessToken) { MailMessage message = new MailMessage( "", "", "NETWORKNET-33499 - " + Guid.NewGuid().ToString(), "Access to SMTP servers using OAuth"); using (SmtpClient client = new SmtpClient("", 587, "", accessToken, true)) { client.Timeout = 400000; client.SecurityMode = SmtpSslSecurityMode.Implicit; client.EnableSsl = true; client.Send(message); } } static void AccessIMAPServer(string accessToken) { using (ImapClient client = new ImapClient("", 993, "", accessToken, true)) { client.EnableSsl = true; client.SecurityMode = ImapSslSecurityMode.Implicit; client.Connect(); client.SelectFolder("Inbox"); ImapMessageInfoCollection messageInfoCol = client.ListMessages(); } } internal static string GetAccessToken(string authorizationCode) { string actionUrl = ""; HttpWebRequest request = (HttpWebRequest)WebRequest.Create(actionUrl); request.CookieContainer = new CookieContainer(); request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; string encodedParameters = string.Format( "client_id={1}&code={0}&client_secret={2}&redirect_uri={3}&grant_type={4}", HttpUtility.UrlEncode(authorizationCode), HttpUtility.UrlEncode(""), HttpUtility.UrlEncode("USnH5eQRsC4XrjJbpGG7WVq5"), HttpUtility.UrlEncode("urn:ietf:wg:oauth:2.0:oob"), HttpUtility.UrlEncode("authorization_code") ); byte[] requestData = Encoding.UTF8.GetBytes(encodedParameters); request.ContentLength = requestData.Length; if (requestData.Length > 0) using (Stream stream = request.GetRequestStream()) stream.Write(requestData, 0, requestData.Length); HttpWebResponse response = (HttpWebResponse)request.GetResponse(); string responseText = null; using (TextReader reader = new StreamReader(response.GetResponseStream(), Encoding.ASCII)) responseText = reader.ReadToEnd(); string accessToken = null; foreach (string sPair in responseText. Replace("{", ""). Replace("}", ""). Replace("\"", ""). Split(new string[] { ",\n" }, StringSplitOptions.None)) { string[] pair = sPair.Split(':'); if ("access_token" == pair[0].Trim()) { accessToken = pair[1].Trim(); break; } } return accessToken; } //[VB.NET Code Sample] Imports Aspose.Email.Mail Imports System.Net Imports Aspose.Email.Imap Imports System.Text Imports System.IO Imports System.Web Module Module1 Sub Main() ' The authorizationCode should be replaced with your value. ' To get authorizationCode use the URL bellow: ' Dim authorizationCode As String = "4/zx4_I4ZhhUdmgLdsejpjeMkwAAMs.kk7o1Qx9U28VOl05ti8ZT3Y1uIlidQI" ' authorizationCode should be replaced with new value !!!!!!! Dim accessToken As String = GetAccessToken(authorizationCode) AccessSMTPServer(accessToken) AccessIMAPServer(accessToken) End Sub Private Sub AccessSMTPServer(ByVal accessToken As String) Dim message As New MailMessage("", "", "NETWORKNET-33499 - " & Guid.NewGuid().ToString(), "Access to SMTP servers using OAuth") Using client As New SmtpClient("", 587, "", accessToken, True) client.Timeout = 400000 client.SecurityMode = SmtpSslSecurityMode.Implicit client.EnableSsl = True client.Send(message) End Using End Sub Private Sub AccessIMAPServer(ByVal accessToken As String) Using client As New ImapClient("", 993, "", accessToken, True) client.EnableSsl = True client.SecurityMode = ImapSslSecurityMode.Implicit client.Connect() client.SelectFolder("Inbox") Dim messageInfoCol As ImapMessageInfoCollection = client.ListMessages() End Using End Sub Friend Function GetAccessToken(ByVal authorizationCode As String) As String Dim actionUrl As String = "" Dim request As HttpWebRequest = DirectCast(WebRequest.Create(actionUrl), HttpWebRequest) request.CookieContainer = New CookieContainer() request.Method = "POST" request.ContentType = "application/x-www-form-urlencoded" Dim encodedParameters As String = String.Format("client_id={1}&code={0}&client_secret={2}&redirect_uri={3}&grant_type={4}", HttpUtility.UrlEncode(authorizationCode), HttpUtility.UrlEncode(""), HttpUtility.UrlEncode("USnH5eQRsC4XrjJbpGG7WVq5"), HttpUtility.UrlEncode("urn:ietf:wg:oauth:2.0:oob"), HttpUtility.UrlEncode("authorization_code")) Dim requestData As Byte() = Encoding.UTF8.GetBytes(encodedParameters) request.ContentLength = requestData.Length If requestData.Length > 0 Then Using stream As IO.Stream = request.GetRequestStream() stream.Write(requestData, 0, requestData.Length) End Using End If Dim response As HttpWebResponse = DirectCast(request.GetResponse(), HttpWebResponse) Dim responseText As String = Nothing Using reader As TextReader = New StreamReader(response.GetResponseStream(), Encoding.ASCII) responseText = reader.ReadToEnd() End Using Dim accessToken As String = Nothing For Each sPair As String In responseText.Replace("{", "").Replace("}", "").Replace("""", "").Split(New String() {"," & vbLf}, StringSplitOptions.None) Dim pair As String() = sPair.Split(":"c) If "access_token" = pair(0).Trim() Then accessToken = pair(1).Trim() Exit For End If Next Return accessToken End Function End Module


Language: C# | User: Sheraz Khan | Created: Jul 15, 2015 | Tags: Access SMTP Server using OAuth Access IMAP Server using OAuth .NET Email component Fetch Messages from IMAP Server Fetch Messages from SMTP Server Connect to an Exchange using IMAP