Lua

Send an SMTP NOOP Command

Demonstrates the Chilkat MailMan.SmtpNoop method, which sends an SMTP NOOP command to the server. NOOP does nothing except elicit a positive response, which is useful for keeping a connection alive or verifying it is still responsive. This example opens an SMTP connection, sends a NOOP, and closes.

Background: When holding an SMTP connection open across many sends (see OpenSmtpConnection), an idle stretch can cause the server to time out and drop the socket. A periodic NOOP keeps the session active and confirms the server is still responding, so the next SendEmail doesn't fail on a silently-closed connection.

Chilkat Lua Downloads

Download Chilkat for Lua

Lua

local chilkat = require("chilkat")

-- Demonstrates the MailMan.SmtpNoop method, which sends an SMTP NOOP command to the server.
-- NOOP does nothing except elicit a positive response, useful for keeping a connection
-- alive or verifying it is still responsive.

local mailman = chilkat.MailMan.new()

-- Configure the SMTP server connection.
mailman.smtp_host = "smtp.example.com"
mailman.smtp_port = 465
mailman.smtp_ssl = true
mailman.smtp_username = "user@example.com"
mailman.smtp_password = "myPassword"

-- Open the SMTP connection.

local success = mailman:open_smtp_connection()
if not success then
    print(mailman.last_error_text)
    return
end

-- Send a NOOP to keep the connection alive.
success = mailman:smtp_noop()
if not success then
    print(mailman.last_error_text)
    return
end

success = mailman:close_smtp_connection()
if not success then
    print(mailman.last_error_text)
    return
end

print("SMTP NOOP succeeded.")