Smtp.BeginSend Method

Begins an asynchronous request for sending a mail message to recipients.

public IAsyncResult BeginSend(
   string senderEmail,
   EmailAddressCollection recipients,
   AsyncCallback callback,
   object state
);

Parameters

senderEmail: The e-mail address of the sender.
recipients: The list of the message recipients.
callback: The AsyncCallback delegate. You can leave it a null reference (Nothing in Visual Basic) if you do not use callbacks.
state: An object that contains state information for this request. You can leave it a null reference (Nothing in Visual Basic).

Return Value

An IAsyncResult that references the asynchronous sending the message.

Remarks

This method is an asynchronous version of Send.

Exceptions

Exception Type	Condition
MailBeeInvalidStateException	There is already an operation in progress.

Example

This WinForms sample sends a mail message asynchronously. The callback function is used to receive notification on asynchronous method completion. Events are used to track send mail progress.

[C#]
// To use the code below, import MailBee namespaces at the top of your code.
using MailBee;
using MailBee.SmtpMail;
using MailBee.DnsMX;
using MailBee.Mime;

// Put the code below inside your class.

// MessageSubmittedToServer event handler.
private void OnMessageSubmittedToServer(object sender,
    SmtpMessageSubmittedToServerEventArgs e)
{
    // If no recipients received the message, this event won't be raised.
    // It's safe to assume AcceptedRecipients collection is not empty.
    string domain = e.AcceptedRecipients[0].GetDomain();
    MessageBox.Show("Message was sent to recipients at " + domain + " domain");
}

// MessageRecipientSubmitted event handler.
private void OnMessageRecipientSubmitted(object sender,
    SmtpMessageRecipientSubmittedEventArgs e)
{
    // If a particular recipient was refused, let the user know.
    if (!e.Result)
    {
        MessageBox.Show("For e-mail address " + e.RecipientEmail +
            ", server responded: " + e.ServerStatusMessage);
    }
}

// Send callback function.
private void SendCallback(IAsyncResult result)
{
    Smtp mailer = (Smtp)result.AsyncState;
    mailer.EndSend();
    MessageBox.Show("The e-mail was sent to: " +
        mailer.GetAcceptedRecipients().ToString());
}

// The actual code.
private void Form1_Load(object sender, System.EventArgs e)
{
    Smtp mailer = new Smtp();

    // Enable logging SMTP session into a file.
    mailer.Log.Enabled = true;
    mailer.Log.Filename = @"C:\log.txt";
    mailer.Log.Clear();
    mailer.Log.Format = LogFormatOptions.AddContextInfo;

    // Get the list of DNS servers for MX lookup from OS settings 
    // (app.config/web.config/machine.config files are ignored).
    mailer.DnsServers.Autodetect(
        DnsAutodetectOptions.Registry | DnsAutodetectOptions.Wmi);

    // Subscribe to events.
    mailer.MessageSubmittedToServer +=
        new SmtpMessageSubmittedToServerEventHandler(OnMessageSubmittedToServer);
    mailer.MessageRecipientSubmitted +=
        new SmtpMessageRecipientSubmittedEventHandler(OnMessageRecipientSubmitted);

    mailer.From.Email = "jdoe@domain.com";
    mailer.Subject = "Important details";

    // Demonstrate different methods of adding To, CC, and BCC recipients. 
    mailer.To.AsString = "kathy@domain.com, \"Bill Smith, Jr.\" <b.smith@company.com>";
    mailer.Cc.Add("Peter", "peter@domain.com");
    mailer.Cc.Add("john@domain.com");
    mailer.Bcc.AsString = "echelon@secret.com";

    // Specify HTML body.
    mailer.BodyHtmlText = "<html>Here are the details.</html>";

    // Create plain-text version.
    mailer.Message.MakePlainBodyFromHtmlBody();

    // Initiate an asynchronous send mail attempt.
    mailer.BeginSend(null, null, new AsyncCallback(SendCallback), mailer);
}