Begins asynchronous KeepAlive operation. Sends the NOOP command to the server to keep the connection alive.

Namespace:  Rebex.Legacy
Assembly:  Rebex.Smtp (in Rebex.Smtp.dll)


Visual Basic
Public Shared Function BeginKeepAlive ( _
	instance As Smtp, _
	callback As AsyncCallback, _
	state As Object _
) As IAsyncResult
public static IAsyncResult BeginKeepAlive(
	Smtp instance,
	AsyncCallback callback,
	Object state


Type: Rebex.Net..::..Smtp
Instance of Smtp.
Type: System..::..AsyncCallback
An optional asynchronous callback to be called when the operation is complete.
Type: System..::..Object
A user-provided object that identifies this particular asynchronous operation.

Return Value

An IAsyncResult that references the asynchronous operation.


Represents SMTP NOOP command.

Call this if you do not want the connection to the server to time out.

Some servers ignore NOOP command.

In builds for .NET 4.0 and higher, this method is available as an extension method. Add 'using Rebex.Legacy' (C#) or 'Import Rebex.Legacy' (VB.NET) to your code in order to use it.

Version Information


Supported in: .NET 6.0, 5.0; .NET Framework 4.8, 4.7.x, 4.6.x, 4.5.x, 4.0

.NET Standard 2.0

Supported in: .NET Core 3.1; .NET Core 2.1; Xamarin.Android 10.1 (or higher); Xamarin.iOS 13.10 (or higher)

See Also