DownloadMessageHeadersCompleted Event

public event ExtendedAsyncCompletedEventHandler<TResult> DownloadMessageHeadersCompleted

Public Event DownloadMessageHeadersCompleted ExtendedAsyncCompletedEventHandler(Of TResult)

public:
 event ExtendedAsyncCompletedEventHandler<TResult>^ DownloadMessageHeadersCompleted

Shows how to connect to a POP3 server and download headers of a message asynchronously.

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

...

// Create a new instance of the Pop3 class.
Pop3 client = new Pop3();

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

// Or you can specify the POP3 port with 
// client.Connect("myserver", 110); 
 
// Login to the server.
client.Authenticate("user", "password");

// ...

MemoryStream stream = new MemoryStream();
// Download a mail message's headers with sequence number 1 to the specified stream. 
await client.DownloadMessageHeadersAsync(1, stream, stream);

// ... 
 
// Load the message for reading.
MailMessage msg = new MailMessage(stream);

Console.WriteLine("Message downloaded successfully.");

foreach (Header h in msg.Headers)
{
    Console.WriteLine("Header Name: {0}, Value: {1}", h.Name, h.Raw);
}

stream.Close();

// Disconnect.
client.Disconnect();

Imports System.IO
Imports ComponentPro.Net.Mail

...

' Create a new instance of the Pop3 class. 
Dim client As New Pop3()

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

' Or you can specify the POP3 port with 
' client.Connect("myserver", 110); 
 
' Login to the server.
client.Authenticate("user", "password")

' ... 
 
Dim stream As New MemoryStream()
' Download a mail message's headers with sequence number 1 to the specified stream. 
Await client.DownloadMessageHeadersAsync(1, stream, stream)

' ... 
 
' Load the message for reading. 
Dim msg As New MailMessage(stream)

Console.WriteLine("Message downloaded successfully.")

For Each h As Header In msg.Headers
    Console.WriteLine("Header Name: {0}, Value: {1}", h.Name, h.Raw)
Next h

stream.Close()

' Disconnect.
client.Disconnect()

Shows how to connect to a POP3 server and download headers of a message asynchronously.

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

...

public void DoDownloadMessageHeadersAsync()
{
    // Create a new instance of the Pop3 class. 
    Pop3 client = new Pop3();

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

    // Or you can specify the POP3 port with 
    // client.Connect("myserver", 110); 
 
    // Login to the server. 
    client.Authenticate("user", "password");

    // ... 
 
    // Register an event handler. 
    client.DownloadMessageHeadersCompleted += client_DownloadMessageHeadersCompleted;

    MemoryStream stream = new MemoryStream();
    // Download a mail message's headers with sequence number 1 to the specified stream. 
    client.DownloadMessageHeadersAsync(1, stream, stream);

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

void client_DownloadMessageHeadersCompleted(object sender, ExtendedAsyncCompletedEventArgs<long> e)
{
    // Pop3 client = (Pop3)sender; 
    if (e.Error != null)
        Console.WriteLine("Error: " + e.Error.ToString());
    else 
    {
        Stream stream = (Stream) e.UserState;
        // Load the message for reading. 
        MailMessage msg = new MailMessage(stream);

        Console.WriteLine("Message downloaded successfully.");
        
        foreach (Header h in msg.Headers)
        {
            Console.WriteLine("Header Name: {0}, Value: {1}", h.Name, h.Raw);
        }

        stream.Close();
    }
}

Imports System.ComponentModel
Imports System.IO
Imports ComponentPro
Imports ComponentPro.Net.Mail

...

Public Sub DoDownloadMessageHeadersAsync()
    ' Create a new instance of the Pop3 class. 
    Dim client As New Pop3()

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

    ' Or you can specify the POP3 port with 
    ' client.Connect("myserver", 110); 
 
    ' Login to the server. 
    client.Authenticate("user", "password")

    ' ... 
 
    ' Register an event handler. 
    AddHandler client.DownloadMessageHeadersCompleted, AddressOf client_DownloadMessageHeadersCompleted

    Dim stream As New MemoryStream()
    ' Download a mail message's headers with sequence number 1 to the specified stream. 
    client.DownloadMessageHeadersAsync(1, stream, stream)

    ' ... 
 
    ' Disconnect. 
    client.Disconnect()
End Sub 
 
Private Sub client_DownloadMessageHeadersCompleted(ByVal sender As Object, ByVal e As ExtendedAsyncCompletedEventArgs(Of Long))
    ' Pop3 client = (Pop3)sender; 
    If e.Error IsNot Nothing Then 
        Console.WriteLine("Error: " & e.Error.ToString())
    Else 
        Dim stream As Stream = CType(e.UserState, Stream)
        ' Load the message for reading. 
        Dim msg As New MailMessage(stream)

        Console.WriteLine("Message downloaded successfully.")

        For Each h As Header In msg.Headers
            Console.WriteLine("Header Name: {0}, Value: {1}", h.Name, h.Raw)
        Next h

        stream.Close()
    End If 
End Sub

Reference