Retrieve Email over SSL connection in C#

In previous section, I introduced how to retrieve email from Exchange Server with WebDAV protocol. In this section, I will introduce how to retrieve email over SSL connection in C#.

Introduction

SSL and TLS

SSL connection encrypts data between the email component and POP3 server or IMAP4 server to protect user, password and email content in TCP/IP level. Now this technology is commonly used and many email servers are deployed with SSL such as Gmail, Yahoo and Hotmail.

There are two ways to deploy SSL on email server:

  • Implicit SSL

    Deploying SSL on another port (POP3: 995 port or IMAP4: 993 port) directly. This is most common way.

  • Explicit SSL (TLS)

    Using STARTTLS or STLS command to switch SSL channel on normal port (POP3: 110 port or IMAP4: 143 port);

EAGetMail POP3 component supports both ways. Please see the following example codes:

For Exchange Web Service/WebDAV protocol, the SSL is based on HTTPS connection, so you just need to set SSLConnection property and simply ignore Port property. Notice: Exchange Web Service requires SSL connection by default.

[C# Example - SSL/TLS]

// Retrieve email by normal TCP/IP without SSL connection
// POP3
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", false,
    ServerAuthType.AuthLogin, ServerProtocol.Pop3);

// IMAP4
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", false,
    ServerAuthType.AuthLogin, ServerProtocol.Imap4);

// Retrieve email over SSL connection with direct SSL.
// POP3 SSL
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", true,
    ServerAuthType.AuthLogin, ServerProtocol.Pop3);
oServer.Port = 995;

// IMAP4 SSL
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", true,
    ServerAuthType.AuthLogin, ServerProtocol.Imap4);
oServer.Port = 993;

// Retrieve email by SSL connection with STARTTLS or TLS command switching
// POP3 TLS
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", true,
    ServerAuthType.AuthLogin, ServerProtocol.Pop3);
oServer.Port = 110;
oServer.SSLType = SSLConnectType.ConnectTLS;

// IMAP4 STARTTLS
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", true,
    ServerAuthType.AuthLogin, ServerProtocol.Imap4);
oServer.Port = 143;
oServer.SSLType = SSLConnectType.ConnectTLS;

// Exchange WebDAV
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", false,
    ServerAuthType.AuthLogin, ServerProtocol.ExchangeWebDAV);

// Exchange Web Service SSL
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", true,
    ServerAuthType.AuthLogin, ServerProtocol.ExchangeEWS);

// Exchange WebDAV SSL
MailServer oServer  = new MailServer("myserveraddress",
    "myuser", "mypassword", true,
    ServerAuthType.AuthLogin, ServerProtocol.ExchangeWebDAV);

Note

Remarks: All of examples in this section are based on first section: A simple C# 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.

[C# Example - Retrieve email from POP3 server over SSL on 995 port]

The following example codes demonstrate how to retrieve emails from POP3 server over SSL connection on 995 port. 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.

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using EAGetMail; //add EAGetMail namespace

namespace receiveemail
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a folder named "inbox" under current directory
            // to save the email retrieved.
            string curpath = Directory.GetCurrentDirectory();
            string mailbox = String.Format("{0}\\inbox", curpath);

            // If the folder is not existed, create it.
            if (!Directory.Exists(mailbox))
            {
                Directory.CreateDirectory(mailbox);
            }

            MailServer oServer = new MailServer("pop3.emailarchitect.net",
                        "test@emailarchitect.net", "testpassword", ServerProtocol.Pop3 );
            MailClient oClient = new MailClient("TryIt");

            // Enable SSL connection.
            oServer.SSLConnection = true;

            // Set 995 SSL port
            oServer.Port = 995;

            try
            {
                oClient.Connect(oServer);
                MailInfo[] infos = oClient.GetMailInfos();
                for (int i = 0; i < infos.Length; i++)
                {
                    MailInfo info = infos[i];
                    Console.WriteLine("Index: {0}; Size: {1}; UIDL: {2}",
                        info.Index, info.Size, info.UIDL);

                    // Receive email from POP3 server
                    Mail oMail = oClient.GetMail(info);

                    Console.WriteLine("From: {0}", oMail.From.ToString());
                    Console.WriteLine("Subject: {0}\r\n", oMail.Subject);

                    // Generate an email file name based on date time.
                    System.DateTime d = System.DateTime.Now;
                    System.Globalization.CultureInfo cur = new
                        System.Globalization.CultureInfo("en-US");
                    string sdate = d.ToString("yyyyMMddHHmmss", cur);
                    string fileName = String.Format("{0}\\{1}{2}{3}.eml",
                        mailbox, sdate, d.Millisecond.ToString("d3"), i);

                    // Save email to local disk
                    oMail.SaveAs(fileName, true);

                    // Mark email as deleted from POP3 server.
                    oClient.Delete(info);
                }

                // Quit and purge emails marked as deleted from POP3 server.
                oClient.Quit();
            }
            catch (Exception ep)
            {
                Console.WriteLine(ep.Message);
            }

        }
    }
}

[C# Example - Retrieve email from IMAP4 server over SSL on 993 port]

The following example codes demonstrate how to retrieve emails from IMAP4 server over SSL connection on 993 port. 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.

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using EAGetMail; //add EAGetMail namespace

namespace receiveemail
{
    class Program
    {
        static void Main(string[] args)
        {
            // Create a folder named "inbox" under current directory
            // to save the email retrieved.
            string curpath = Directory.GetCurrentDirectory();
            string mailbox = String.Format("{0}\\inbox", curpath);

            // If the folder is not existed, create it.
            if (!Directory.Exists(mailbox))
            {
                Directory.CreateDirectory(mailbox);
            }

            MailServer oServer = new MailServer("imap.emailarchitect.net",
                        "test@emailarchitect.net", "testpassword", ServerProtocol.Imap4 );
            MailClient oClient = new MailClient("TryIt");

            // Enable SSL connection.
            oServer.SSLConnection = true;

            // Set 993 SSL port
            oServer.Port = 993;

            try
            {
                oClient.Connect(oServer);
                MailInfo[] infos = oClient.GetMailInfos();
                for (int i = 0; i < infos.Length; i++)
                {
                    MailInfo info = infos[i];
                    Console.WriteLine("Index: {0}; Size: {1}; UIDL: {2}",
                        info.Index, info.Size, info.UIDL);

                    // Receive email from IMAP server
                    Mail oMail = oClient.GetMail(info);

                    Console.WriteLine("From: {0}", oMail.From.ToString());
                    Console.WriteLine("Subject: {0}\r\n", oMail.Subject);

                    // Generate an email file name based on date time.
                    System.DateTime d = System.DateTime.Now;
                    System.Globalization.CultureInfo cur = new
                        System.Globalization.CultureInfo("en-US");
                    string sdate = d.ToString("yyyyMMddHHmmss", cur);
                    string fileName = String.Format("{0}\\{1}{2}{3}.eml",
                        mailbox, sdate, d.Millisecond.ToString("d3"), i);

                    // Save email to local disk
                    oMail.SaveAs(fileName, true);

                    // Mark email as deleted from IMAP server.
                    oClient.Delete(info);
                }

                // Quit and purge emails marked as deleted from IMAP server.
                oClient.Quit();
            }
            catch (Exception ep)
            {
                Console.WriteLine(ep.Message);
            }

        }
    }
}

Next Section

At next section I will introduce how to download emails from Gmail account.

Appendix

Comments

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