Código de PHP - Envio de correo mediante servidor SMTP

$smtp->SMTPAuth   = true;

$smtp->SMTPSecure = "tls";

$smtp->Host       = "smtp.live.com";

$smtp->Username   = "miCuenta@outlook.com";

$smtp->Password   = "miPassword";

$smtp->Port       = 25;

$smtp->SMTPAuth   = true;

$smtp->SMTPSecure = "tls";

$smtp->Host       = "smtp.gmail.com";

$smtp->Username   = "miCuenta@gmail.com";

$smtp->Password   = "miPassword";

$smtp->Port       = 587;

$smtp->SMTPAuth   = true;

$smtp->SMTPSecure = "ssl";

$smtp->Host       = "smtp.mail.yahoo.com";

$smtp->Username   = "miCuenta@yahoo.com";

$smtp->Password   = "miPassword";

$smtp->Port       = 465;