Progress Event

public event EventHandler<TEventArgs> Progress

Public Event Progress EventHandler(Of TEventArgs)

public:
 event EventHandler<TEventArgs>^ Progress

Show how to handle the Progress event.

using System;
using ComponentPro.Net.Mail;

...

public void ShowProgress()
{
    // Create a new Smtp instance. 
    Smtp client = new Smtp();

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

    // Authenticate. 
    client.Authenticate("test", "test");

    try 
    {
        // Register an event handler. 
        client.Progress += client_Progress;

        // Load an existing mail message. 
        MailMessage msg = new MailMessage("c:\\temp\\my message.eml");

        // And send it. 
        client.Send(msg);
    }
    catch (SmtpException exc)
    {
        Console.WriteLine("Exception: " + exc.Message);
    }

    // Disconnect. 
    client.Disconnect();
}

void client_Progress(object sender, SmtpProgressEventArgs e)
{
    // Show progress information. 
    if (e.State == SmtpTransferState.Sending)
    {
        Console.Write("\rDownloaded: {0} bytes ({1}% completed)", e.BytesTransferred, e.Percentage);
    }
}

Imports ComponentPro.Net.Mail

...

Public Sub ShowProgress()
    ' Create a new Smtp instance. 
    Dim client As New Smtp()

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

    ' Authenticate. 
    client.Authenticate("test", "test")

    Try 
        ' Register an event handler. 
        AddHandler client.Progress, AddressOf client_Progress

        ' Load an existing mail message. 
        Dim msg As New MailMessage("c:\temp\my message.eml")

        ' And send it. 
        client.Send(msg)
    Catch exc As SmtpException
        Console.WriteLine("Exception: " & exc.Message)
    End Try 
 
    ' Disconnect. 
    client.Disconnect()
End Sub 
 
Private Sub client_Progress(ByVal sender As Object, ByVal e As SmtpProgressEventArgs)
    ' Show progress information. 
    If e.State = SmtpTransferState.Sending Then 
        Console.Write(vbCr & "Downloaded: {0} bytes ({1}% completed)", e.BytesTransferred, e.Percentage)
    End If 
End Sub

Reference