VB.NET

Send a POP3 NOOP Command

Demonstrates the Chilkat MailMan.Pop3Noop method, which sends a POP3 NOOP command to the server. NOOP does nothing except elicit a positive response, which is useful for keeping a session alive or verifying the connection is still responsive. This example begins a POP3 session and sends a NOOP.

Background: NOOP ("no operation") is a standard keep-alive across many internet protocols. Servers often drop idle connections after a timeout; sending a periodic NOOP resets that timer so a long-running session stays open. It also serves as a cheap "are you still there?" probe — a successful reply confirms the socket and the authenticated session are still healthy.

Chilkat VB.NET Downloads

Download Chilkat for VB.NET

VB.NET

Dim success As Boolean = False

'  Demonstrates the MailMan.Pop3Noop method, which sends a POP3 NOOP command to the server.
'  NOOP does nothing except elicit a positive response, which is useful for keeping a
'  session alive or verifying the connection is still responsive.

Dim mailman As New Chilkat.MailMan

'  Configure the POP3 server connection.
mailman.MailHost = "pop.example.com"
mailman.MailPort = 995
mailman.PopSsl = True
mailman.PopUsername = "user@example.com"
mailman.PopPassword = "myPassword"

'  Begin a POP3 session.

success = mailman.Pop3BeginSession()
If (success = False) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


'  Send a NOOP to keep the session alive.
success = mailman.Pop3Noop()
If (success = False) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("POP3 NOOP succeeded.")