[ObsoleteAttribute("This method is obsolete in .NET 4.5+. Use HelloAsync instead.")]
public IAsyncResult BeginHello(
	AsyncCallback callback,
	Object state
)

<ObsoleteAttribute("This method is obsolete in .NET 4.5+. Use HelloAsync instead.")>
Public Function BeginHello ( 
	callback As AsyncCallback,
	state As Object
) As IAsyncResult

using System;
using MailBee;
using MailBee.SmtpMail;

class Sample
{
    // ErrorOccurred event handler.
    private static void OnErrorOccurred(object sender, ErrorEventArgs e)
    {
        if (e.Reason is MailBeeSmtpOptionalCommandNotSupportedException)
        {
            Console.WriteLine(e.Reason.Message); // EHLO not supported.
        }
    }

    // The actual code.
    static void Main(string[] args)
    {
        Smtp mailer = new Smtp();

        mailer.SmtpServers.Add("mail.domain.com");

        mailer.Connect();

        // Subscribe to the ErrorOccurred event. We subcribe only for the time 
        // of Hello() method execution to make sure the trapped warnings do not 
        // relate to execution of any other methods.
        mailer.ErrorOccurred += new ErrorEventHandler(OnErrorOccurred);

        // Initiate an asynchronous greeting.
        mailer.BeginHello(null, null);

        // Simulate some lengthy work here. At the same time, 
        // the greeting is performed on another thread.
        System.Threading.Thread.Sleep(1000);

        // End the connection request.
        mailer.EndHello();

        mailer.ErrorOccurred -= new ErrorEventHandler(OnErrorOccurred);

        mailer.Disconnect();
    }
}

Imports System
Imports MailBee
Imports MailBee.SmtpMail

Class Sample
    ' ErrorOccurred event handler.
    Private Shared Sub OnErrorOccurred(ByVal sender As Object, ByVal e As ErrorEventArgs)
        If (TypeOf e.Reason Is MailBeeSmtpOptionalCommandNotSupportedException) Then
            Console.WriteLine(e.Reason.Message)' EHLO not supported.
        End If
    End Sub

    ' The actual code.
    Shared Sub Main(ByVal args As String())
        Dim mailer As New Smtp

        mailer.SmtpServers.Add("mail.domain.com")

        mailer.Connect()

        ' Subscribe to the ErrorOccurred event. We subcribe only for the time 
        ' of Hello() method execution to make sure the trapped warnings do not 
        ' relate to execution of any other methods.
        AddHandler mailer.ErrorOccurred, AddressOf OnErrorOccurred

        ' Initiate an asynchronous greeting.
        mailer.BeginHello(Nothing, Nothing)

        ' Simulate some lengthy work here. At the same time, 
        ' the greeting is performed on another thread.
        System.Threading.Thread.Sleep(1000)

        ' End the connection request.
        mailer.EndHello()

        RemoveHandler mailer.ErrorOccurred, AddressOf OnErrorOccurred

        mailer.Disconnect()
    End Sub
End Class