[ObsoleteAttribute("This method is obsolete in .NET 4.5+. Use SetMessageFlagsAsync instead.")]
public IAsyncResult BeginSetMessageFlags(
	string messageIndexSet,
	bool indexIsUid,
	string flags,
	MessageFlagAction action,
	bool silentMode,
	AsyncCallback callback,
	Object state
)

<ObsoleteAttribute("This method is obsolete in .NET 4.5+. Use SetMessageFlagsAsync instead.")>
Public Function BeginSetMessageFlags ( 
	messageIndexSet As String,
	indexIsUid As Boolean,
	flags As String,
	action As MessageFlagAction,
	silentMode As Boolean,
	callback As AsyncCallback,
	state As Object
) As IAsyncResult

// To use the code below, import MailBee namespaces at the top of your code.
using MailBee;
using MailBee.ImapMail;

// Put the code below inside your class.

bool finished;
bool started = false;

// A callback function. Since it's called on Imap worker thread,
// it cannot display any messages or otherwise access UI.
// Any updates of UI must take place on message loop thread.
// See the sample in BeginSearch() topic on how to update UI in
// such scenario.
private void SetMessageFlagsCallback(IAsyncResult result)
{
    Imap imp = (Imap)result.AsyncState;

    // It's important to handle exceptions in worker threads. Otherwise,
    // the worker thread could silently die and the application would
    // have never known this had happened.
    try
    {
        imp.EndSetMessageFlags();
        imp.Expunge();
    }
    catch (MailBeeException e)
    {
        MessageBox.Show(e.Message);
    }
    finally
    {
        finished = true;
    }
}

// Add button1 on the form to make this sample working.
private void button1_Click(object sender, System.EventArgs e)
{
    if (started)
    {
        MessageBox.Show("The operation is already in progress");
    }
    else
    {
        started = true;
    }

    finished = false;

    Imap imp = new Imap();

    // Connect to the server, login and select inbox.
    imp.Connect("mail.company.com");
    imp.Login("jdoe", "secret");
    imp.SelectFolder("Inbox");

    // Asynchronously mark the first message as deleted. Instead of
    // MessageFlagSet.SystemFlagsToString(SystemMessageFlags.Deleted),
    // we could simply use "\Deleted" (@"\Deleted" in C#).
    imp.BeginSetMessageFlags("1", false,
        MessageFlagSet.SystemFlagsToString(SystemMessageFlags.Deleted),
        MessageFlagAction.Add, true,
        new AsyncCallback(SetMessageFlagsCallback), imp);

    // Wait until completion via periodic polling
    // of the completion status.
    while (!finished)
    {
        System.Threading.Thread.Sleep(1);

        // It's not necessary to call DoEvents here since we do not
        // handle any MailBee events in this sample. However, if we did,
        // we would have needed this call to let the events be processed.
        // Alternatively, we could have set imp.RaiseEventsViaMessageLoop
        // to false and use imp.Wait() instead of Thread.Sleep() and
        // Application.DoEvents(). If using imp.Wait(), we would not need
        // to prevent this routine from being called again while it's
        // already being executed since imp.Wait() blocks UI and it would
        // be impossible to click a button until imp.Wait() completes.
        Application.DoEvents();
    }

    // Disconnect from the server.
    imp.Disconnect();

    started = false;
}

' To use the code below, import MailBee namespaces at the top of your code.
Imports MailBee
Imports MailBee.ImapMail

' Put the code below inside your class.

Dim finished As Boolean
Dim started As Boolean = False

' A callback function. Since it's called on Imap worker thread,
' it cannot display any messages or otherwise access UI.
' Any updates of UI must take place on message loop thread.
' See the sample in BeginSearch() topic on how to update UI in
' such scenario.
Private Sub SetMessageFlagsCallback(ByVal result As IAsyncResult)
    Dim imp As Imap = CType(result.AsyncState, Imap)

    ' It's important to handle exceptions in worker threads. Otherwise,
    ' the worker thread could silently die and the application would
    ' have never known this had happened.
    Try
        imp.EndSetMessageFlags()
        imp.Expunge()
    Catch e As MailBeeException
        MessageBox.Show(e.Message)
    Finally
        finished = True
    End Try
End Sub

' Add button1 on the form to make this sample working.
Private Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
    If started Then
        MessageBox.Show("The operation is already in progress")
    Else
        started = True
    End If

    finished = False

    Dim imp As New Imap

    ' Connect to the server, login and select inbox.
    imp.Connect("mail.company.com")
    imp.Login("jdoe", "secret")
    imp.SelectFolder("Inbox")

    ' Asynchronously mark the first message as deleted. Instead of
    ' MessageFlagSet.SystemFlagsToString(SystemMessageFlags.Deleted),
    ' we could simply use "\Deleted" ("\Deleted" in Visual Basic).
    imp.BeginSetMessageFlags("1", False, _
        MessageFlagSet.SystemFlagsToString(SystemMessageFlags.Deleted), _
        MessageFlagAction.Add, True, New AsyncCallback(AddressOf SetMessageFlagsCallback), imp)

    ' Wait until completion via periodic polling
    ' of the completion status.
    While Not finished
        System.Threading.Thread.Sleep(1)

        ' It's not necessary to call DoEvents here since we do not
        ' handle any MailBee events in this sample. However, if we did,
        ' we would have needed this call to let the events be processed.
        ' Alternatively, we could have set imp.RaiseEventsViaMessageLoop
        ' to false and use imp.Wait() instead of Thread.Sleep() and
        ' Application.DoEvents(). If using imp.Wait(), we would not need
        ' to prevent this routine from being called again while it's
        ' already being executed since imp.Wait() blocks UI and it would
        ' be impossible to click a button until imp.Wait() completes.
        Application.DoEvents()
    End While

    ' Disconnect from the server.
    imp.Disconnect()

    started = False
End Sub