Download/Retrieve Email from Gmail account in C#

In previous section, I introduced how to retrieve email over SSL connection. In this section, I will introduce how to download email from your Gmail account in C#.

Introduction

Gmail POP3 server address is pop.gmail.com. It requires SSL connection on 995 port, and you should use your Gmail email address as the user name for user authentication.

Gmail IMAP4 server address is imap.gmail.com. It requires SSL connection on 993 port, and you should use your Gmail email address as the user name for user authentication. For example: your email is gmailid@gmail.com, and then the user name should be gmailid@gmail.com.

To retrieve email from Gmail account, you need to enable POP3 or IMAP4 access in your gmail account settings.

Because Gmail POP3 server doesn’t work like normal POP3 server, it hides old emails automatically even the email was not deleted, so we suggest that you use IMAP4 protocol.

Server Port SSL Protocol
pop.gmail.com 995 SSL required Pop3
imap.gmail.com 993 SSL required Imap4 (recommended)

Important

If you got authentication error, you need to enable Allowing less secure apps or Sign in using App Passwords.

Another way is Gmail OAUH, please see Gmail IMAP OAUTH section.

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 Gmail account]

The following example codes demonstrate how to download email from Gmail account using IMAP4 protocol.

Because Gmail POP3 server doesn’t work like normal POP3 server, it hides old emails automatically even the email was not deleted, so we suggest that you use IMAP4 protocol.

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);
            }

            // Gmail IMAP4 server is "imap.gmail.com"
            MailServer oServer = new MailServer("imap.gmail.com",
                        "gmailid@gmail.com", "yourpassword", ServerProtocol.Imap4 );
            MailClient oClient = new MailClient("TryIt");

            // Set SSL connection,
            oServer.SSLConnection = true;

            // Set 993 IMAP4 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);

                    // Download email from GMail IMAP4 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 in GMail account.
                    oClient.Delete(info);
                }

                // Quit and purge emails marked as deleted from Gmail IMAP4 server.
                oClient.Quit();
            }
            catch (Exception ep)
            {
                Console.WriteLine(ep.Message);
            }

        }
    }
}

Gmail IMAP OAUTH

The Gmail IMAP and SMTP servers have been extended to support authorization via the industry-standard OAuth 2.0 protocol. Using OAUTH protocol, user can do authentication by Gmail Web OAuth instead of inputting user and password directly in application. This way is more secure, but a little bit complex.

Using Gmail IMAP OAUTH

Next Section

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

Appendix

Comments

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