Reading emails from Gmail in C#

Question

I am trying to read emails from Gmail. I have tried every API / open source project I can find, and can not get any of them working.

Does anyone have a sample of working code that will allow me to authenticate and download emails from a Gmail account?

Final working version posted below: https://stackoverflow.com/a/19570553/550198

Answer 1

Using the library from: https://github.com/pmengal/MailSystem.NET

Here is my complete code sample:

Email Repository

using System.Collections.Generic;
using System.Linq;
using ActiveUp.Net.Mail;

namespace GmailReadImapEmail
{
    public class MailRepository
    {
        private Imap4Client client;

        public MailRepository(string mailServer, int port, bool ssl, string login, string password)
        {
            if (ssl)
                Client.ConnectSsl(mailServer, port);
            else
                Client.Connect(mailServer, port);
            Client.Login(login, password);
        }

        public IEnumerable<Message> GetAllMails(string mailBox)
        {
            return GetMails(mailBox, "ALL").Cast<Message>();
        }

        public IEnumerable<Message> GetUnreadMails(string mailBox)
        {
            return GetMails(mailBox, "UNSEEN").Cast<Message>();
        }

        protected Imap4Client Client
        {
            get { return client ?? (client = new Imap4Client()); }
        }

        private MessageCollection GetMails(string mailBox, string searchPhrase)
        {
            Mailbox mails = Client.SelectMailbox(mailBox);
            MessageCollection messages = mails.SearchParse(searchPhrase);
            return messages;
        }
    }
}

Usage

[TestMethod]
public void ReadImap()
{
    var mailRepository = new MailRepository(
                            "imap.gmail.com",
                            993,
                            true,
                            "[email protected]",
                            "yourPassword"
                        );

    var emailList = mailRepository.GetAllMails("inbox");

    foreach (Message email in emailList)
    {
        Console.WriteLine("<p>{0}: {1}</p><p>{2}</p>", email.From, email.Subject, email.BodyHtml.Text);
        if (email.Attachments.Count > 0)
        {
            foreach (MimePart attachment in email.Attachments)
            {
                Console.WriteLine("<p>Attachment: {0} {1}</p>", attachment.ContentName, attachment.ContentType.MimeType);
            }
        }
    }
}

---

Another example, this time using MailKit

public class MailRepository : IMailRepository
{
    private readonly string mailServer, login, password;
    private readonly int port;
    private readonly bool ssl;

    public MailRepository(string mailServer, int port, bool ssl, string login, string password)
    {
        this.mailServer = mailServer;
        this.port = port;
        this.ssl = ssl;
        this.login = login;
        this.password = password;
    }

    public IEnumerable<string> GetUnreadMails()
    {
        var messages = new List<string>();

        using (var client = new ImapClient())
        {
            client.Connect(mailServer, port, ssl);

            // Note: since we don't have an OAuth2 token, disable
            // the XOAUTH2 authentication mechanism.
            client.AuthenticationMechanisms.Remove("XOAUTH2");

            client.Authenticate(login, password);

            // The Inbox folder is always available on all IMAP servers...
            var inbox = client.Inbox;
            inbox.Open(FolderAccess.ReadOnly);
            var results = inbox.Search(SearchOptions.All, SearchQuery.Not(SearchQuery.Seen));
            foreach (var uniqueId in results.UniqueIds)
            {
                var message = inbox.GetMessage(uniqueId);

                messages.Add(message.HtmlBody);

                //Mark message as read
                //inbox.AddFlags(uniqueId, MessageFlags.Seen, true);
            }

            client.Disconnect(true);
        }

        return messages;
    }

    public IEnumerable<string> GetAllMails()
    {
        var messages = new List<string>();

        using (var client = new ImapClient())
        {
            client.Connect(mailServer, port, ssl);

            // Note: since we don't have an OAuth2 token, disable
            // the XOAUTH2 authentication mechanism.
            client.AuthenticationMechanisms.Remove("XOAUTH2");

            client.Authenticate(login, password);

            // The Inbox folder is always available on all IMAP servers...
            var inbox = client.Inbox;
            inbox.Open(FolderAccess.ReadOnly);
            var results = inbox.Search(SearchOptions.All, SearchQuery.NotSeen);
            foreach (var uniqueId in results.UniqueIds)
            {
                var message = inbox.GetMessage(uniqueId);

                messages.Add(message.HtmlBody);

                //Mark message as read
                //inbox.AddFlags(uniqueId, MessageFlags.Seen, true);
            }

            client.Disconnect(true);
        }

        return messages;
    }
}

Usage

[Test]
public void GetAllEmails()
{
    var mailRepository = new MailRepository("imap.gmail.com", 993, true, "[email protected]", "YOURPASSWORDHERE");
    var allEmails = mailRepository.GetAllMails();

    foreach(var email in allEmails)
    {
        Console.WriteLine(email);
    }

    Assert.IsTrue(allEmails.ToList().Any());
}

Answer 2

You don't need any extra 3rd Party Libraries if a summary of the 20 most recent emails is sufficient for you. You can read the data from API that Gmail has provided here: https://mail.google.com/mail/feed/atom

The response in XML format can be handled by the code below:

try {
    const string emailAddress = "YourEmail";
    // App Password, not password
    // See: https://support.google.com/accounts/answer/185833?hl=en
    const string appPassword = "YourAppPassword";

    string response;
    string title;
    string summary;
    XmlDocument xmlDocument = new XmlDocument();

    HttpClient httpClient = new HttpClient();

    // Logging in Gmail server to get data
    httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.UTF8.GetBytes($"{emailAddress}:{appPassword}")));

    // Reading data and converting to string
    response = await httpClient.GetStringAsync(@"https://mail.google.com/mail/feed/atom");

    // Remove XML namespace to simplify parsing/selecting nodes
    response = response.Replace(@"<feed version=""0.3"" xmlns=""http://purl.org/atom/ns#"">", @"<feed>");

    // Loading into an XML so we can get information easily
    xmlDocument.LoadXml(response);

    // Amount of emails
    string nr = xmlDocument.SelectSingleNode(@"/feed/fullcount").InnerText;

    // Reading the title and the summary for every email
    foreach (XmlNode node in xmlDocument.SelectNodes(@"/feed/entry")) {
        title = node.SelectSingleNode("title").InnerText;
        summary = node.SelectSingleNode("summary").InnerText;

        Console.WriteLine($"> {title}");
        Console.WriteLine($"{summary}");
        Console.WriteLine();
    }
} catch (Exception ex) {
    MessageBox.Show($"Error retrieving mails: {ex.Message}");
}