FolderExistsCompleted Event

public event ExtendedAsyncCompletedEventHandler<TResult> FolderExistsCompleted

Public Event FolderExistsCompleted ExtendedAsyncCompletedEventHandler(Of TResult)

public:
 event ExtendedAsyncCompletedEventHandler<TResult>^ FolderExistsCompleted

Connect to an IMAP server and asynchronously check if a mailbox exists (Task-based asynchronous approach).

using System;
using ComponentPro.Net.Mail;

...

// 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 the 'INBOX' folder.
client.Select("INBOX");

// Check to see whether 'my folder' mailbox exists in the current working mailbox. 
bool exists = await client.FolderExistsAsync("my folder");

// ... 
 
if (exists)
    Console.WriteLine("Folder exists");
else 
    Console.WriteLine("Folder does not exists");

// Disconnect.
client.Disconnect();

Imports ComponentPro.Net.Mail

...

' 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 the 'INBOX' folder.
client.Select("INBOX")

' Check to see whether 'my folder' mailbox exists in the current working mailbox. 
Dim exists As Boolean = Await client.FolderExistsAsync("my folder")

' ... 
 
If exists Then 
    Console.WriteLine("Folder exists")
Else 
    Console.WriteLine("Folder does not exists")
End If 
 
' Disconnect.
client.Disconnect()

Connect to an IMAP server and asynchronously check if a mailbox exists (Event-based asynchronous approach).

using System;
using ComponentPro;
using ComponentPro.Net.Mail;

...

public void DoFolderExistsAsync()
{
    // 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");

    // ... 
 
    // Register an event handler. 
    client.FolderExistsCompleted += client_FolderExistsCompleted;

    // Select the 'INBOX' folder. 
    client.Select("INBOX");

    // Check to see whether 'my folder' mailbox exists in the current working mailbox. 
    client.FolderExistsAsync("my folder");

    // ... 
 
    // Disconnect. 
    client.Disconnect();
}

void client_FolderExistsCompleted(object sender, ExtendedAsyncCompletedEventArgs<bool> e)
{
    // Imap client = (Imap)sender; 
    if (e.Error != null)
    {
        Console.WriteLine("Error: " + e.Error.ToString());
    }
    else 
    {
        if (e.Result)
            Console.WriteLine("Folder exists");
        else 
            Console.WriteLine("Folder does not exists");
    }
    
}

Imports ComponentPro
Imports ComponentPro.Net.Mail

...

Public Sub DoFolderExistsAsync()
    ' 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")

    ' ... 
 
    ' Register an event handler. 
    AddHandler client.FolderExistsCompleted, AddressOf client_FolderExistsCompleted

    ' Select the 'INBOX' folder. 
    client.Select("INBOX")

    ' Check to see whether 'my folder' mailbox exists in the current working mailbox. 
    client.FolderExistsAsync("my folder")

    ' ... 
 
    ' Disconnect. 
    client.Disconnect()
End Sub 
 
Private Sub client_FolderExistsCompleted(ByVal sender As Object, ByVal e As ExtendedAsyncCompletedEventArgs(Of Boolean))
    ' Imap client = (Imap)sender; 
    If e.Error IsNot Nothing Then 
        Console.WriteLine("Error: " & e.Error.ToString())
    Else 
        If e.Result Then 
            Console.WriteLine("Folder exists")
        Else 
            Console.WriteLine("Folder does not exists")
        End If 
    End If 
 
End Sub

Reference