Retrieve Email from IMAP4 server in C#¶

In previous section, I introduced retrieving email from POP3 server in C#. In this section, I will introduce the IMAP4 server.

Sections:

Introduction
[C# Example - Retrieve email from IMAP4 inbox]
[C# Example - Retrieve email from “Deleted Items”]
TLS 1.2

Introduction¶

IMAP4 protocol is different with POP3 protocol. First of all, IMAP4 supports retrieving email from different mail folder and folder management. Secondly, IMAP4 supports mail flags management. Therefore, we can do more things with IMAP4 server. To better understand the IMAP4 protocol, please see the following examples.

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 IMAP4 inbox]¶

The following example codes demonstrate how to download email from IMAP4 server default mailbox. 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.Globalization;
using System.IO;
using EAGetMail; //add EAGetMail namespace

namespace receiveemail
{
    class Program
    {
        // Generate an unqiue email file name based on date time
        static string _generateFileName(int sequence)
        {
            DateTime currentDateTime = DateTime.Now;
            return string.Format("{0}-{1:000}-{2:000}.eml",
                currentDateTime.ToString("yyyyMMddHHmmss", new CultureInfo("en-US")),
                currentDateTime.Millisecond,
                sequence);
        }

        static void Main(string[] args)
        {
            try
            {
                // Create a folder named "inbox" under current directory
                // to save the email retrieved.
                string localInbox = string.Format("{0}\\inbox", Directory.GetCurrentDirectory());
                // If the folder is not existed, create it.
                if (!Directory.Exists(localInbox))
                {
                    Directory.CreateDirectory(localInbox);
                }

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

                // Enable SSL/TLS connection, most modern email server require SSL/TLS by default
                oServer.SSLConnection = true;
                oServer.Port = 993;

                // if your server doesn't support SSL/TLS, please use the following codes
                // oServer.SSLConnection = false;
                // oServer.Port = 143;

                MailClient oClient = new MailClient("TryIt");
                oClient.Connect(oServer);

                MailInfo[] infos = oClient.GetMailInfos();
                Console.WriteLine("Total {0} email(s)\r\n", infos.Length);
                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 IMAP4 server
                    Mail oMail = oClient.GetMail(info);

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

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

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

                    // Mark email as deleted from IMAP4 server.
                    oClient.Delete(info);
                }

                // Quit and expunge emails marked as deleted from IMAP4 server.
                oClient.Quit();
                Console.WriteLine("Completed!");
            }
            catch (Exception ep)
            {
                Console.WriteLine(ep.Message);
            }
        }
    }
}

Because IMAP4 protocol supports folder access, so we can retrieve email from other mailbox rather than default “INBOX”. POP3 protocol doesn’t support this feature.

[C# Example - Retrieve email from “Deleted Items”]¶

The following example codes demonstrate how to retrieve emails from “Deleted Items” in an IMAP4 account. 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.Globalization;
using System.IO;
using EAGetMail; //add EAGetMail namespace

namespace receiveemail
{
    class Program
    {
        // if you want to search sub folder, use parentfolder\subfolder as folderPath
        // for example: inbox\mysubfolder
        static Imap4Folder FindFolder(string folderPath, Imap4Folder[] folders)
        {
            int count = folders.Length;
            for (int i = 0; i < count; i++)
            {
                Imap4Folder folder = folders[i];
                if (string.Compare(folder.LocalPath, folderPath, true) == 0)
                {
                    return folder;
                }

                folder = FindFolder(folderPath, folder.SubFolders);
                if (folder != null)
                {
                    return folder;
                }
            }

            // No folder found
            return null;
        }

        // Generate an unqiue email file name based on date time
        static string _generateFileName(int sequence)
        {
            DateTime currentDateTime = DateTime.Now;
            return string.Format("{0}-{1:000}-{2:000}.eml",
                currentDateTime.ToString("yyyyMMddHHmmss", new CultureInfo("en-US")),
                currentDateTime.Millisecond,
                sequence);
        }

        static void Main(string[] args)
        {
            try
            {
                // Create a folder named "inbox" under current directory
                // to save the email retrieved.
                string localInbox = string.Format("{0}\\inbox", Directory.GetCurrentDirectory());
                // If the folder is not existed, create it.
                if (!Directory.Exists(localInbox))
                {
                    Directory.CreateDirectory(localInbox);
                }

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

                // Enable SSL/TLS connection, most modern email server require SSL/TLS by default
                oServer.SSLConnection = true;
                oServer.Port = 993;

                // if your server doesn't support SSL/TLS, please use the following codes
                // oServer.SSLConnection = false;
                // oServer.Port = 143;

                MailClient oClient = new MailClient("TryIt");
                oClient.Connect(oServer);

                // find folder
                Imap4Folder folder = FindFolder("Deleted Items", oClient.GetFolders());
                if (folder == null)
                {
                    throw new Exception("Folder not found!");
                }

                // select dest folder
                oClient.SelectFolder(folder);

                MailInfo[] infos = oClient.GetMailInfos();
                Console.WriteLine("Total {0} email(s)\r\n", infos.Length);
                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 IMAP4 server
                    Mail oMail = oClient.GetMail(info);

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

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

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

                    // Mark email as deleted from IMAP4 server.
                    oClient.Delete(info);
                }

                // Quit and expunge emails marked as deleted from IMAP4 server.
                oClient.Quit();
                Console.WriteLine("Completed!");
            }
            catch (Exception ep)
            {
                Console.WriteLine(ep.Message);
            }
        }
    }
}

TLS 1.2¶

TLS is the successor of SSL, more and more Email servers require TLS 1.2 encryption now.

If your operating system is Windows XP/Vista/Windows 7/Windows 2003/2008/2008 R2/2012/2012 R2, and you got connection error with SSL/TLS connection, you need to enable TLS 1.2 protocol in your operating system like this:

Enable TLS 1.2 on Windows XP/Vista/7/10/Windows 2008/2008 R2/2012

Next Section

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

Tutorial Index

Retrieve Email from IMAP4 server in C#¶

Introduction¶

[C# Example - Retrieve email from IMAP4 inbox]¶

[C# Example - Retrieve email from “Deleted Items”]¶

TLS 1.2¶

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