SubscribeCompleted Event

public event AsyncCompletedEventHandler SubscribeCompleted

Public Event SubscribeCompleted AsyncCompletedEventHandler

public:
 event AsyncCompletedEventHandler^ SubscribeCompleted

Connect to an IMAP server and subscribe/unsubscribe a folder asynchronously (Task-based asynchronous approach).

using System;
using System.ComponentModel;
using System.Text;
using ComponentPro;
using ComponentPro.Net.Mail;

...

// Create a new instance of the Imap class.
Imap client = new Imap();

// Connect to the server. 
await client.ConnectAsync("myserver");

// Or you can specify the IMAP port with 
// client.Connect("myserver", 143); 
 
// Login to the server. 
await client.AuthenticateAsync("user", "password");

// ... 
 
// Select 'INBOX' mailbox.
client.Select("INBOX");

// ... 
 
await client.SubscribeAsync("my folder");

Console.WriteLine("Folder unsubscribed.");

StringBuilder sb = new StringBuilder("Subscribed Folders: ");

FolderCollection list = await client.ListFoldersAsync("", true);
for (int i = 0; i < list.Count; i++)
{
    sb.AppendFormat("{0} - {1}\r\n", i + 1, list[i].Name);
}

// ... 
 
// Later we can unsubscribe the folder. 
await client.UnsubscribeAsync("my folder");

Console.WriteLine("Folder unsubscribed.");

// Disconnect.
client.Disconnect();

Imports System.ComponentModel
Imports System.Text
Imports ComponentPro
Imports ComponentPro.Net.Mail

...

' Create a new instance of the Imap class. 
Dim client As New Imap()

' Connect to the server. 
Await client.ConnectAsync("myserver")

' Or you can specify the IMAP port with 
' client.Connect("myserver", 143); 
 
' Login to the server. 
Await client.AuthenticateAsync("user", "password")

' ... 
 
' Select 'INBOX' mailbox.
client.Select("INBOX")

' ... 
 
Await client.SubscribeAsync("my folder")

Console.WriteLine("Folder unsubscribed.")

Dim sb As New StringBuilder("Subscribed Folders: ")

Dim list As FolderCollection = Await client.ListFoldersAsync("", True)
For i As Integer = 0 To list.Count - 1
    sb.AppendFormat("{0} - {1}" & vbCrLf, i + 1, list(i).Name)
Next i

' ... 
 
' Later we can unsubscribe the folder. 
Await client.UnsubscribeAsync("my folder")

Console.WriteLine("Folder unsubscribed.")

' Disconnect.
client.Disconnect()

Connect to an IMAP server and subscribe/unsubscribe a folder asynchronously (Event-based asynchronous approach).

using System;
using System.ComponentModel;
using System.Text;
using ComponentPro;
using ComponentPro.Net.Mail;

...

public void DoSubscribeAsync()
{
    // Create a new instance of the Imap class. 
    Imap client = new Imap();

    // Connect to the server. 
    client.Connect("myserver");

    // Or you can specify the IMAP port with 
    // client.Connect("myserver", 143); 
 
    // Login to the server. 
    client.Authenticate("user", "password");

    // ... 
 
    // Select 'INBOX' mailbox. 
    client.Select("INBOX");

    // ... 
 
    client.SubscribeCompleted += client_SubscribeCompleted;
    client.UnsubscribeCompleted += new AsyncCompletedEventHandler(client_UnsubscribeCompleted);

    client.SubscribeAsync("my folder");

    // ... 
 
    // Later we can unsubscribe the folder. 
    client.UnsubscribeAsync("my folder");

    // Disconnect. 
    client.Disconnect();
}

void client_UnsubscribeCompleted(object sender, AsyncCompletedEventArgs e)
{
    // Imap client = (Imap)sender; 
    if (e.Error != null)
        Console.WriteLine("Error: " + e.Error.ToString());
    else 
    {
        Console.WriteLine("Folder unsubscribed.");
    }
}

void client_SubscribeCompleted(object sender, AsyncCompletedEventArgs e)
{
    Imap client = (Imap)sender;
    if (e.Error != null)
        Console.WriteLine("Error: " + e.Error.ToString());
    else 
    {
        StringBuilder sb = new StringBuilder("Subscribed Folders: ");

        FolderCollection list = client.ListFolders("", true);
        for (int i = 0; i < list.Count; i++)
        {
            sb.AppendFormat("{0} - {1}\r\n", i + 1, list[i].Name);
        }
    }
}

Imports System.ComponentModel
Imports System.Text
Imports ComponentPro
Imports ComponentPro.Net.Mail

...

Public Sub DoSubscribeAsync()
    ' Create a new instance of the Imap class. 
    Dim client As New Imap()

    ' Connect to the server. 
    client.Connect("myserver")

    ' Or you can specify the IMAP port with 
    ' client.Connect("myserver", 143); 
 
    ' Login to the server. 
    client.Authenticate("user", "password")

    ' ... 
 
    ' Select 'INBOX' mailbox. 
    client.Select("INBOX")

    ' ... 
 
    AddHandler client.SubscribeCompleted, AddressOf client_SubscribeCompleted
    AddHandler client.UnsubscribeCompleted, AddressOf client_UnsubscribeCompleted

    client.SubscribeAsync("my folder")

    ' ... 
 
    ' Later we can unsubscribe the folder. 
    client.UnsubscribeAsync("my folder")

    ' Disconnect. 
    client.Disconnect()
End Sub 
 
Private Sub client_UnsubscribeCompleted(ByVal sender As Object, ByVal e As AsyncCompletedEventArgs)
    ' Imap client = (Imap)sender; 
    If e.Error IsNot Nothing Then 
        Console.WriteLine("Error: " & e.Error.ToString())
    Else 
        Console.WriteLine("Folder unsubscribed.")
    End If 
End Sub 
 
Private Sub client_SubscribeCompleted(ByVal sender As Object, ByVal e As AsyncCompletedEventArgs)
    Dim client As Imap = CType(sender, Imap)
    If e.Error IsNot Nothing Then 
        Console.WriteLine("Error: " & e.Error.ToString())
    Else 
        Dim sb As New StringBuilder("Subscribed Folders: ")

        Dim list As FolderCollection = client.ListFolders("", True)
        For i As Integer = 0 To list.Count - 1
            sb.AppendFormat("{0} - {1}" & vbCrLf, i + 1, list(i).Name)
        Next i
    End If 
End Sub

Reference