IMAP Client in C# and VB.NET

Internet Message Access Protocol (IMAP) is currently the most used protocol for managing an email box by multiple clients or devices. It has replaced the older POP protocol due to its advanced features, which include, but are not limited to, folders, flags and search support, and asynchronous updates by IDLE extension.

GemBox.Email enables you to work with the IMAP protocol in C# and VB.NET using an ImapClient class. It supports the latest version (version 4; IMAP4) defined in RFC 3501. To learn about how to receive an email and how to connect with some common IMAP4 servers (like Gmail, Outlook, Yahoo, etc.), visit our Receive example.

The following example shows how you can create a new ImapClient and use it to connect to, authenticate and disconnect from a remote IMAP4 server.

using System;
using GemBox.Email;
using GemBox.Email.Imap;

class Program
{
    static void Main()
    {
        // If using the Professional version, put your serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        // Create new IMAP client.
        using (var imap = new ImapClient("<ADDRESS> (e.g. imap.gmail.com)"))
        {
            // By default the connect timeout is 5 sec.
            imap.ConnectTimeout = TimeSpan.FromSeconds(4);

            // Connect to IMAP server.
            imap.Connect();
            Console.WriteLine("Connected.");

            // Authenticate using the credentials; username and password.
            imap.Authenticate("<USERNAME>", "<PASSWORD>");
            Console.WriteLine("Authenticated.");
        }

        Console.WriteLine("Disconnected.");
    }
}

Imports System
Imports GemBox.Email
Imports GemBox.Email.Imap

Module Program

    Sub Main()

        ' If using the Professional version, put your serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        ' Create new IMAP client.
        Using imap As New ImapClient("<ADDRESS> (e.g. imap.gmail.com)")

            ' By default the connect timeout is 5 sec.
            imap.ConnectTimeout = TimeSpan.FromSeconds(4)

            ' Connect to IMAP server.
            imap.Connect()
            Console.WriteLine("Connected.")

            ' Authenticate using the credentials; username and password.
            imap.Authenticate("<USERNAME>", "<PASSWORD>")
            Console.WriteLine("Authenticated.")
        End Using

        Console.WriteLine("Disconnected.")
    End Sub
End Module

You can reuse the same connection that's established by the ImapClient object and your email server multiple times.

When calling the ImapClient.Authenticate method, the strongest possible password-based authentication mechanism will be used from the ImapClient.SupportedAuthentications collection.

To disconnect from the email server, you can use either the ImapClient.Disconnect or ImapClient.Dispose method.

Last, ImapClient utilizes the following protocol's extensions:

• IDLE
• STARTTLS
• LOGINDISABLED
• MOVE